1 //===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Stmt nodes as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "CGDebugInfo.h"
14 #include "CGOpenMPRuntime.h"
15 #include "CodeGenFunction.h"
16 #include "CodeGenModule.h"
17 #include "CodeGenPGO.h"
18 #include "TargetInfo.h"
19 #include "clang/AST/Attr.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/Stmt.h"
22 #include "clang/AST/StmtVisitor.h"
23 #include "clang/Basic/Builtins.h"
24 #include "clang/Basic/DiagnosticSema.h"
25 #include "clang/Basic/PrettyStackTrace.h"
26 #include "clang/Basic/SourceManager.h"
27 #include "clang/Basic/TargetInfo.h"
28 #include "llvm/ADT/ArrayRef.h"
29 #include "llvm/ADT/DenseMap.h"
30 #include "llvm/ADT/SmallSet.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/Assumptions.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/InlineAsm.h"
35 #include "llvm/IR/Intrinsics.h"
36 #include "llvm/IR/MDBuilder.h"
37 #include "llvm/Support/SaveAndRestore.h"
38 #include <optional>
39
40 using namespace clang;
41 using namespace CodeGen;
42
43 //===----------------------------------------------------------------------===//
44 // Statement Emission
45 //===----------------------------------------------------------------------===//
46
47 namespace llvm {
48 extern cl::opt<bool> EnableSingleByteCoverage;
49 } // namespace llvm
50
EmitStopPoint(const Stmt * S)51 void CodeGenFunction::EmitStopPoint(const Stmt *S) {
52 if (CGDebugInfo *DI = getDebugInfo()) {
53 SourceLocation Loc;
54 Loc = S->getBeginLoc();
55 DI->EmitLocation(Builder, Loc);
56
57 LastStopPoint = Loc;
58 }
59 }
60
EmitStmt(const Stmt * S,ArrayRef<const Attr * > Attrs)61 void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) {
62 assert(S && "Null statement?");
63 PGO->setCurrentStmt(S);
64
65 // These statements have their own debug info handling.
66 if (EmitSimpleStmt(S, Attrs))
67 return;
68
69 // Check if we are generating unreachable code.
70 if (!HaveInsertPoint()) {
71 // If so, and the statement doesn't contain a label, then we do not need to
72 // generate actual code. This is safe because (1) the current point is
73 // unreachable, so we don't need to execute the code, and (2) we've already
74 // handled the statements which update internal data structures (like the
75 // local variable map) which could be used by subsequent statements.
76 if (!ContainsLabel(S)) {
77 // Verify that any decl statements were handled as simple, they may be in
78 // scope of subsequent reachable statements.
79 assert(!isa<DeclStmt>(*S) && "Unexpected DeclStmt!");
80 PGO->markStmtMaybeUsed(S);
81 return;
82 }
83
84 // Otherwise, make a new block to hold the code.
85 EnsureInsertPoint();
86 }
87
88 // Generate a stoppoint if we are emitting debug info.
89 EmitStopPoint(S);
90
91 // Ignore all OpenMP directives except for simd if OpenMP with Simd is
92 // enabled.
93 if (getLangOpts().OpenMP && getLangOpts().OpenMPSimd) {
94 if (const auto *D = dyn_cast<OMPExecutableDirective>(S)) {
95 EmitSimpleOMPExecutableDirective(*D);
96 return;
97 }
98 }
99
100 switch (S->getStmtClass()) {
101 case Stmt::NoStmtClass:
102 case Stmt::CXXCatchStmtClass:
103 case Stmt::SEHExceptStmtClass:
104 case Stmt::SEHFinallyStmtClass:
105 case Stmt::MSDependentExistsStmtClass:
106 llvm_unreachable("invalid statement class to emit generically");
107 case Stmt::NullStmtClass:
108 case Stmt::CompoundStmtClass:
109 case Stmt::DeclStmtClass:
110 case Stmt::LabelStmtClass:
111 case Stmt::AttributedStmtClass:
112 case Stmt::GotoStmtClass:
113 case Stmt::BreakStmtClass:
114 case Stmt::ContinueStmtClass:
115 case Stmt::DefaultStmtClass:
116 case Stmt::CaseStmtClass:
117 case Stmt::SEHLeaveStmtClass:
118 case Stmt::SYCLKernelCallStmtClass:
119 llvm_unreachable("should have emitted these statements as simple");
120
121 #define STMT(Type, Base)
122 #define ABSTRACT_STMT(Op)
123 #define EXPR(Type, Base) \
124 case Stmt::Type##Class:
125 #include "clang/AST/StmtNodes.inc"
126 {
127 // Remember the block we came in on.
128 llvm::BasicBlock *incoming = Builder.GetInsertBlock();
129 assert(incoming && "expression emission must have an insertion point");
130
131 EmitIgnoredExpr(cast<Expr>(S));
132
133 llvm::BasicBlock *outgoing = Builder.GetInsertBlock();
134 assert(outgoing && "expression emission cleared block!");
135
136 // The expression emitters assume (reasonably!) that the insertion
137 // point is always set. To maintain that, the call-emission code
138 // for noreturn functions has to enter a new block with no
139 // predecessors. We want to kill that block and mark the current
140 // insertion point unreachable in the common case of a call like
141 // "exit();". Since expression emission doesn't otherwise create
142 // blocks with no predecessors, we can just test for that.
143 // However, we must be careful not to do this to our incoming
144 // block, because *statement* emission does sometimes create
145 // reachable blocks which will have no predecessors until later in
146 // the function. This occurs with, e.g., labels that are not
147 // reachable by fallthrough.
148 if (incoming != outgoing && outgoing->use_empty()) {
149 outgoing->eraseFromParent();
150 Builder.ClearInsertionPoint();
151 }
152 break;
153 }
154
155 case Stmt::IndirectGotoStmtClass:
156 EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break;
157
158 case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break;
159 case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S), Attrs); break;
160 case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S), Attrs); break;
161 case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S), Attrs); break;
162
163 case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break;
164
165 case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break;
166 case Stmt::GCCAsmStmtClass: // Intentional fall-through.
167 case Stmt::MSAsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break;
168 case Stmt::CoroutineBodyStmtClass:
169 EmitCoroutineBody(cast<CoroutineBodyStmt>(*S));
170 break;
171 case Stmt::CoreturnStmtClass:
172 EmitCoreturnStmt(cast<CoreturnStmt>(*S));
173 break;
174 case Stmt::CapturedStmtClass: {
175 const CapturedStmt *CS = cast<CapturedStmt>(S);
176 EmitCapturedStmt(*CS, CS->getCapturedRegionKind());
177 }
178 break;
179 case Stmt::ObjCAtTryStmtClass:
180 EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S));
181 break;
182 case Stmt::ObjCAtCatchStmtClass:
183 llvm_unreachable(
184 "@catch statements should be handled by EmitObjCAtTryStmt");
185 case Stmt::ObjCAtFinallyStmtClass:
186 llvm_unreachable(
187 "@finally statements should be handled by EmitObjCAtTryStmt");
188 case Stmt::ObjCAtThrowStmtClass:
189 EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S));
190 break;
191 case Stmt::ObjCAtSynchronizedStmtClass:
192 EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S));
193 break;
194 case Stmt::ObjCForCollectionStmtClass:
195 EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S));
196 break;
197 case Stmt::ObjCAutoreleasePoolStmtClass:
198 EmitObjCAutoreleasePoolStmt(cast<ObjCAutoreleasePoolStmt>(*S));
199 break;
200
201 case Stmt::CXXTryStmtClass:
202 EmitCXXTryStmt(cast<CXXTryStmt>(*S));
203 break;
204 case Stmt::CXXForRangeStmtClass:
205 EmitCXXForRangeStmt(cast<CXXForRangeStmt>(*S), Attrs);
206 break;
207 case Stmt::SEHTryStmtClass:
208 EmitSEHTryStmt(cast<SEHTryStmt>(*S));
209 break;
210 case Stmt::OMPMetaDirectiveClass:
211 EmitOMPMetaDirective(cast<OMPMetaDirective>(*S));
212 break;
213 case Stmt::OMPCanonicalLoopClass:
214 EmitOMPCanonicalLoop(cast<OMPCanonicalLoop>(S));
215 break;
216 case Stmt::OMPParallelDirectiveClass:
217 EmitOMPParallelDirective(cast<OMPParallelDirective>(*S));
218 break;
219 case Stmt::OMPSimdDirectiveClass:
220 EmitOMPSimdDirective(cast<OMPSimdDirective>(*S));
221 break;
222 case Stmt::OMPTileDirectiveClass:
223 EmitOMPTileDirective(cast<OMPTileDirective>(*S));
224 break;
225 case Stmt::OMPStripeDirectiveClass:
226 EmitOMPStripeDirective(cast<OMPStripeDirective>(*S));
227 break;
228 case Stmt::OMPUnrollDirectiveClass:
229 EmitOMPUnrollDirective(cast<OMPUnrollDirective>(*S));
230 break;
231 case Stmt::OMPReverseDirectiveClass:
232 EmitOMPReverseDirective(cast<OMPReverseDirective>(*S));
233 break;
234 case Stmt::OMPInterchangeDirectiveClass:
235 EmitOMPInterchangeDirective(cast<OMPInterchangeDirective>(*S));
236 break;
237 case Stmt::OMPForDirectiveClass:
238 EmitOMPForDirective(cast<OMPForDirective>(*S));
239 break;
240 case Stmt::OMPForSimdDirectiveClass:
241 EmitOMPForSimdDirective(cast<OMPForSimdDirective>(*S));
242 break;
243 case Stmt::OMPSectionsDirectiveClass:
244 EmitOMPSectionsDirective(cast<OMPSectionsDirective>(*S));
245 break;
246 case Stmt::OMPSectionDirectiveClass:
247 EmitOMPSectionDirective(cast<OMPSectionDirective>(*S));
248 break;
249 case Stmt::OMPSingleDirectiveClass:
250 EmitOMPSingleDirective(cast<OMPSingleDirective>(*S));
251 break;
252 case Stmt::OMPMasterDirectiveClass:
253 EmitOMPMasterDirective(cast<OMPMasterDirective>(*S));
254 break;
255 case Stmt::OMPCriticalDirectiveClass:
256 EmitOMPCriticalDirective(cast<OMPCriticalDirective>(*S));
257 break;
258 case Stmt::OMPParallelForDirectiveClass:
259 EmitOMPParallelForDirective(cast<OMPParallelForDirective>(*S));
260 break;
261 case Stmt::OMPParallelForSimdDirectiveClass:
262 EmitOMPParallelForSimdDirective(cast<OMPParallelForSimdDirective>(*S));
263 break;
264 case Stmt::OMPParallelMasterDirectiveClass:
265 EmitOMPParallelMasterDirective(cast<OMPParallelMasterDirective>(*S));
266 break;
267 case Stmt::OMPParallelSectionsDirectiveClass:
268 EmitOMPParallelSectionsDirective(cast<OMPParallelSectionsDirective>(*S));
269 break;
270 case Stmt::OMPTaskDirectiveClass:
271 EmitOMPTaskDirective(cast<OMPTaskDirective>(*S));
272 break;
273 case Stmt::OMPTaskyieldDirectiveClass:
274 EmitOMPTaskyieldDirective(cast<OMPTaskyieldDirective>(*S));
275 break;
276 case Stmt::OMPErrorDirectiveClass:
277 EmitOMPErrorDirective(cast<OMPErrorDirective>(*S));
278 break;
279 case Stmt::OMPBarrierDirectiveClass:
280 EmitOMPBarrierDirective(cast<OMPBarrierDirective>(*S));
281 break;
282 case Stmt::OMPTaskwaitDirectiveClass:
283 EmitOMPTaskwaitDirective(cast<OMPTaskwaitDirective>(*S));
284 break;
285 case Stmt::OMPTaskgroupDirectiveClass:
286 EmitOMPTaskgroupDirective(cast<OMPTaskgroupDirective>(*S));
287 break;
288 case Stmt::OMPFlushDirectiveClass:
289 EmitOMPFlushDirective(cast<OMPFlushDirective>(*S));
290 break;
291 case Stmt::OMPDepobjDirectiveClass:
292 EmitOMPDepobjDirective(cast<OMPDepobjDirective>(*S));
293 break;
294 case Stmt::OMPScanDirectiveClass:
295 EmitOMPScanDirective(cast<OMPScanDirective>(*S));
296 break;
297 case Stmt::OMPOrderedDirectiveClass:
298 EmitOMPOrderedDirective(cast<OMPOrderedDirective>(*S));
299 break;
300 case Stmt::OMPAtomicDirectiveClass:
301 EmitOMPAtomicDirective(cast<OMPAtomicDirective>(*S));
302 break;
303 case Stmt::OMPTargetDirectiveClass:
304 EmitOMPTargetDirective(cast<OMPTargetDirective>(*S));
305 break;
306 case Stmt::OMPTeamsDirectiveClass:
307 EmitOMPTeamsDirective(cast<OMPTeamsDirective>(*S));
308 break;
309 case Stmt::OMPCancellationPointDirectiveClass:
310 EmitOMPCancellationPointDirective(cast<OMPCancellationPointDirective>(*S));
311 break;
312 case Stmt::OMPCancelDirectiveClass:
313 EmitOMPCancelDirective(cast<OMPCancelDirective>(*S));
314 break;
315 case Stmt::OMPTargetDataDirectiveClass:
316 EmitOMPTargetDataDirective(cast<OMPTargetDataDirective>(*S));
317 break;
318 case Stmt::OMPTargetEnterDataDirectiveClass:
319 EmitOMPTargetEnterDataDirective(cast<OMPTargetEnterDataDirective>(*S));
320 break;
321 case Stmt::OMPTargetExitDataDirectiveClass:
322 EmitOMPTargetExitDataDirective(cast<OMPTargetExitDataDirective>(*S));
323 break;
324 case Stmt::OMPTargetParallelDirectiveClass:
325 EmitOMPTargetParallelDirective(cast<OMPTargetParallelDirective>(*S));
326 break;
327 case Stmt::OMPTargetParallelForDirectiveClass:
328 EmitOMPTargetParallelForDirective(cast<OMPTargetParallelForDirective>(*S));
329 break;
330 case Stmt::OMPTaskLoopDirectiveClass:
331 EmitOMPTaskLoopDirective(cast<OMPTaskLoopDirective>(*S));
332 break;
333 case Stmt::OMPTaskLoopSimdDirectiveClass:
334 EmitOMPTaskLoopSimdDirective(cast<OMPTaskLoopSimdDirective>(*S));
335 break;
336 case Stmt::OMPMasterTaskLoopDirectiveClass:
337 EmitOMPMasterTaskLoopDirective(cast<OMPMasterTaskLoopDirective>(*S));
338 break;
339 case Stmt::OMPMaskedTaskLoopDirectiveClass:
340 EmitOMPMaskedTaskLoopDirective(cast<OMPMaskedTaskLoopDirective>(*S));
341 break;
342 case Stmt::OMPMasterTaskLoopSimdDirectiveClass:
343 EmitOMPMasterTaskLoopSimdDirective(
344 cast<OMPMasterTaskLoopSimdDirective>(*S));
345 break;
346 case Stmt::OMPMaskedTaskLoopSimdDirectiveClass:
347 EmitOMPMaskedTaskLoopSimdDirective(
348 cast<OMPMaskedTaskLoopSimdDirective>(*S));
349 break;
350 case Stmt::OMPParallelMasterTaskLoopDirectiveClass:
351 EmitOMPParallelMasterTaskLoopDirective(
352 cast<OMPParallelMasterTaskLoopDirective>(*S));
353 break;
354 case Stmt::OMPParallelMaskedTaskLoopDirectiveClass:
355 EmitOMPParallelMaskedTaskLoopDirective(
356 cast<OMPParallelMaskedTaskLoopDirective>(*S));
357 break;
358 case Stmt::OMPParallelMasterTaskLoopSimdDirectiveClass:
359 EmitOMPParallelMasterTaskLoopSimdDirective(
360 cast<OMPParallelMasterTaskLoopSimdDirective>(*S));
361 break;
362 case Stmt::OMPParallelMaskedTaskLoopSimdDirectiveClass:
363 EmitOMPParallelMaskedTaskLoopSimdDirective(
364 cast<OMPParallelMaskedTaskLoopSimdDirective>(*S));
365 break;
366 case Stmt::OMPDistributeDirectiveClass:
367 EmitOMPDistributeDirective(cast<OMPDistributeDirective>(*S));
368 break;
369 case Stmt::OMPTargetUpdateDirectiveClass:
370 EmitOMPTargetUpdateDirective(cast<OMPTargetUpdateDirective>(*S));
371 break;
372 case Stmt::OMPDistributeParallelForDirectiveClass:
373 EmitOMPDistributeParallelForDirective(
374 cast<OMPDistributeParallelForDirective>(*S));
375 break;
376 case Stmt::OMPDistributeParallelForSimdDirectiveClass:
377 EmitOMPDistributeParallelForSimdDirective(
378 cast<OMPDistributeParallelForSimdDirective>(*S));
379 break;
380 case Stmt::OMPDistributeSimdDirectiveClass:
381 EmitOMPDistributeSimdDirective(cast<OMPDistributeSimdDirective>(*S));
382 break;
383 case Stmt::OMPTargetParallelForSimdDirectiveClass:
384 EmitOMPTargetParallelForSimdDirective(
385 cast<OMPTargetParallelForSimdDirective>(*S));
386 break;
387 case Stmt::OMPTargetSimdDirectiveClass:
388 EmitOMPTargetSimdDirective(cast<OMPTargetSimdDirective>(*S));
389 break;
390 case Stmt::OMPTeamsDistributeDirectiveClass:
391 EmitOMPTeamsDistributeDirective(cast<OMPTeamsDistributeDirective>(*S));
392 break;
393 case Stmt::OMPTeamsDistributeSimdDirectiveClass:
394 EmitOMPTeamsDistributeSimdDirective(
395 cast<OMPTeamsDistributeSimdDirective>(*S));
396 break;
397 case Stmt::OMPTeamsDistributeParallelForSimdDirectiveClass:
398 EmitOMPTeamsDistributeParallelForSimdDirective(
399 cast<OMPTeamsDistributeParallelForSimdDirective>(*S));
400 break;
401 case Stmt::OMPTeamsDistributeParallelForDirectiveClass:
402 EmitOMPTeamsDistributeParallelForDirective(
403 cast<OMPTeamsDistributeParallelForDirective>(*S));
404 break;
405 case Stmt::OMPTargetTeamsDirectiveClass:
406 EmitOMPTargetTeamsDirective(cast<OMPTargetTeamsDirective>(*S));
407 break;
408 case Stmt::OMPTargetTeamsDistributeDirectiveClass:
409 EmitOMPTargetTeamsDistributeDirective(
410 cast<OMPTargetTeamsDistributeDirective>(*S));
411 break;
412 case Stmt::OMPTargetTeamsDistributeParallelForDirectiveClass:
413 EmitOMPTargetTeamsDistributeParallelForDirective(
414 cast<OMPTargetTeamsDistributeParallelForDirective>(*S));
415 break;
416 case Stmt::OMPTargetTeamsDistributeParallelForSimdDirectiveClass:
417 EmitOMPTargetTeamsDistributeParallelForSimdDirective(
418 cast<OMPTargetTeamsDistributeParallelForSimdDirective>(*S));
419 break;
420 case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass:
421 EmitOMPTargetTeamsDistributeSimdDirective(
422 cast<OMPTargetTeamsDistributeSimdDirective>(*S));
423 break;
424 case Stmt::OMPInteropDirectiveClass:
425 EmitOMPInteropDirective(cast<OMPInteropDirective>(*S));
426 break;
427 case Stmt::OMPDispatchDirectiveClass:
428 CGM.ErrorUnsupported(S, "OpenMP dispatch directive");
429 break;
430 case Stmt::OMPScopeDirectiveClass:
431 EmitOMPScopeDirective(cast<OMPScopeDirective>(*S));
432 break;
433 case Stmt::OMPMaskedDirectiveClass:
434 EmitOMPMaskedDirective(cast<OMPMaskedDirective>(*S));
435 break;
436 case Stmt::OMPGenericLoopDirectiveClass:
437 EmitOMPGenericLoopDirective(cast<OMPGenericLoopDirective>(*S));
438 break;
439 case Stmt::OMPTeamsGenericLoopDirectiveClass:
440 EmitOMPTeamsGenericLoopDirective(cast<OMPTeamsGenericLoopDirective>(*S));
441 break;
442 case Stmt::OMPTargetTeamsGenericLoopDirectiveClass:
443 EmitOMPTargetTeamsGenericLoopDirective(
444 cast<OMPTargetTeamsGenericLoopDirective>(*S));
445 break;
446 case Stmt::OMPParallelGenericLoopDirectiveClass:
447 EmitOMPParallelGenericLoopDirective(
448 cast<OMPParallelGenericLoopDirective>(*S));
449 break;
450 case Stmt::OMPTargetParallelGenericLoopDirectiveClass:
451 EmitOMPTargetParallelGenericLoopDirective(
452 cast<OMPTargetParallelGenericLoopDirective>(*S));
453 break;
454 case Stmt::OMPParallelMaskedDirectiveClass:
455 EmitOMPParallelMaskedDirective(cast<OMPParallelMaskedDirective>(*S));
456 break;
457 case Stmt::OMPAssumeDirectiveClass:
458 EmitOMPAssumeDirective(cast<OMPAssumeDirective>(*S));
459 break;
460 case Stmt::OpenACCComputeConstructClass:
461 EmitOpenACCComputeConstruct(cast<OpenACCComputeConstruct>(*S));
462 break;
463 case Stmt::OpenACCLoopConstructClass:
464 EmitOpenACCLoopConstruct(cast<OpenACCLoopConstruct>(*S));
465 break;
466 case Stmt::OpenACCCombinedConstructClass:
467 EmitOpenACCCombinedConstruct(cast<OpenACCCombinedConstruct>(*S));
468 break;
469 case Stmt::OpenACCDataConstructClass:
470 EmitOpenACCDataConstruct(cast<OpenACCDataConstruct>(*S));
471 break;
472 case Stmt::OpenACCEnterDataConstructClass:
473 EmitOpenACCEnterDataConstruct(cast<OpenACCEnterDataConstruct>(*S));
474 break;
475 case Stmt::OpenACCExitDataConstructClass:
476 EmitOpenACCExitDataConstruct(cast<OpenACCExitDataConstruct>(*S));
477 break;
478 case Stmt::OpenACCHostDataConstructClass:
479 EmitOpenACCHostDataConstruct(cast<OpenACCHostDataConstruct>(*S));
480 break;
481 case Stmt::OpenACCWaitConstructClass:
482 EmitOpenACCWaitConstruct(cast<OpenACCWaitConstruct>(*S));
483 break;
484 case Stmt::OpenACCInitConstructClass:
485 EmitOpenACCInitConstruct(cast<OpenACCInitConstruct>(*S));
486 break;
487 case Stmt::OpenACCShutdownConstructClass:
488 EmitOpenACCShutdownConstruct(cast<OpenACCShutdownConstruct>(*S));
489 break;
490 case Stmt::OpenACCSetConstructClass:
491 EmitOpenACCSetConstruct(cast<OpenACCSetConstruct>(*S));
492 break;
493 case Stmt::OpenACCUpdateConstructClass:
494 EmitOpenACCUpdateConstruct(cast<OpenACCUpdateConstruct>(*S));
495 break;
496 case Stmt::OpenACCAtomicConstructClass:
497 EmitOpenACCAtomicConstruct(cast<OpenACCAtomicConstruct>(*S));
498 break;
499 case Stmt::OpenACCCacheConstructClass:
500 EmitOpenACCCacheConstruct(cast<OpenACCCacheConstruct>(*S));
501 break;
502 }
503 }
504
EmitSimpleStmt(const Stmt * S,ArrayRef<const Attr * > Attrs)505 bool CodeGenFunction::EmitSimpleStmt(const Stmt *S,
506 ArrayRef<const Attr *> Attrs) {
507 switch (S->getStmtClass()) {
508 default:
509 return false;
510 case Stmt::NullStmtClass:
511 break;
512 case Stmt::CompoundStmtClass:
513 EmitCompoundStmt(cast<CompoundStmt>(*S));
514 break;
515 case Stmt::DeclStmtClass:
516 EmitDeclStmt(cast<DeclStmt>(*S));
517 break;
518 case Stmt::LabelStmtClass:
519 EmitLabelStmt(cast<LabelStmt>(*S));
520 break;
521 case Stmt::AttributedStmtClass:
522 EmitAttributedStmt(cast<AttributedStmt>(*S));
523 break;
524 case Stmt::GotoStmtClass:
525 EmitGotoStmt(cast<GotoStmt>(*S));
526 break;
527 case Stmt::BreakStmtClass:
528 EmitBreakStmt(cast<BreakStmt>(*S));
529 break;
530 case Stmt::ContinueStmtClass:
531 EmitContinueStmt(cast<ContinueStmt>(*S));
532 break;
533 case Stmt::DefaultStmtClass:
534 EmitDefaultStmt(cast<DefaultStmt>(*S), Attrs);
535 break;
536 case Stmt::CaseStmtClass:
537 EmitCaseStmt(cast<CaseStmt>(*S), Attrs);
538 break;
539 case Stmt::SEHLeaveStmtClass:
540 EmitSEHLeaveStmt(cast<SEHLeaveStmt>(*S));
541 break;
542 case Stmt::SYCLKernelCallStmtClass:
543 // SYCL kernel call statements are generated as wrappers around the body
544 // of functions declared with the sycl_kernel_entry_point attribute. Such
545 // functions are used to specify how a SYCL kernel (a function object) is
546 // to be invoked; the SYCL kernel call statement contains a transformed
547 // variation of the function body and is used to generate a SYCL kernel
548 // caller function; a function that serves as the device side entry point
549 // used to execute the SYCL kernel. The sycl_kernel_entry_point attributed
550 // function is invoked by host code in order to trigger emission of the
551 // device side SYCL kernel caller function and to generate metadata needed
552 // by SYCL run-time library implementations; the function is otherwise
553 // intended to have no effect. As such, the function body is not evaluated
554 // as part of the invocation during host compilation (and the function
555 // should not be called or emitted during device compilation); the SYCL
556 // kernel call statement is thus handled as a null statement for the
557 // purpose of code generation.
558 break;
559 }
560 return true;
561 }
562
563 /// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true,
564 /// this captures the expression result of the last sub-statement and returns it
565 /// (for use by the statement expression extension).
EmitCompoundStmt(const CompoundStmt & S,bool GetLast,AggValueSlot AggSlot)566 Address CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast,
567 AggValueSlot AggSlot) {
568 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),S.getLBracLoc(),
569 "LLVM IR generation of compound statement ('{}')");
570
571 // Keep track of the current cleanup stack depth, including debug scopes.
572 LexicalScope Scope(*this, S.getSourceRange());
573
574 return EmitCompoundStmtWithoutScope(S, GetLast, AggSlot);
575 }
576
577 Address
EmitCompoundStmtWithoutScope(const CompoundStmt & S,bool GetLast,AggValueSlot AggSlot)578 CodeGenFunction::EmitCompoundStmtWithoutScope(const CompoundStmt &S,
579 bool GetLast,
580 AggValueSlot AggSlot) {
581
582 const Stmt *ExprResult = S.getStmtExprResult();
583 assert((!GetLast || (GetLast && ExprResult)) &&
584 "If GetLast is true then the CompoundStmt must have a StmtExprResult");
585
586 Address RetAlloca = Address::invalid();
587
588 for (auto *CurStmt : S.body()) {
589 if (GetLast && ExprResult == CurStmt) {
590 // We have to special case labels here. They are statements, but when put
591 // at the end of a statement expression, they yield the value of their
592 // subexpression. Handle this by walking through all labels we encounter,
593 // emitting them before we evaluate the subexpr.
594 // Similar issues arise for attributed statements.
595 while (!isa<Expr>(ExprResult)) {
596 if (const auto *LS = dyn_cast<LabelStmt>(ExprResult)) {
597 EmitLabel(LS->getDecl());
598 ExprResult = LS->getSubStmt();
599 } else if (const auto *AS = dyn_cast<AttributedStmt>(ExprResult)) {
600 // FIXME: Update this if we ever have attributes that affect the
601 // semantics of an expression.
602 ExprResult = AS->getSubStmt();
603 } else {
604 llvm_unreachable("unknown value statement");
605 }
606 }
607
608 EnsureInsertPoint();
609
610 const Expr *E = cast<Expr>(ExprResult);
611 QualType ExprTy = E->getType();
612 if (hasAggregateEvaluationKind(ExprTy)) {
613 EmitAggExpr(E, AggSlot);
614 } else {
615 // We can't return an RValue here because there might be cleanups at
616 // the end of the StmtExpr. Because of that, we have to emit the result
617 // here into a temporary alloca.
618 RetAlloca = CreateMemTemp(ExprTy);
619 EmitAnyExprToMem(E, RetAlloca, Qualifiers(),
620 /*IsInit*/ false);
621 }
622 } else {
623 EmitStmt(CurStmt);
624 }
625 }
626
627 return RetAlloca;
628 }
629
SimplifyForwardingBlocks(llvm::BasicBlock * BB)630 void CodeGenFunction::SimplifyForwardingBlocks(llvm::BasicBlock *BB) {
631 llvm::BranchInst *BI = dyn_cast<llvm::BranchInst>(BB->getTerminator());
632
633 // If there is a cleanup stack, then we it isn't worth trying to
634 // simplify this block (we would need to remove it from the scope map
635 // and cleanup entry).
636 if (!EHStack.empty())
637 return;
638
639 // Can only simplify direct branches.
640 if (!BI || !BI->isUnconditional())
641 return;
642
643 // Can only simplify empty blocks.
644 if (BI->getIterator() != BB->begin())
645 return;
646
647 BB->replaceAllUsesWith(BI->getSuccessor(0));
648 BI->eraseFromParent();
649 BB->eraseFromParent();
650 }
651
EmitBlock(llvm::BasicBlock * BB,bool IsFinished)652 void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB, bool IsFinished) {
653 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
654
655 // Fall out of the current block (if necessary).
656 EmitBranch(BB);
657
658 if (IsFinished && BB->use_empty()) {
659 delete BB;
660 return;
661 }
662
663 // Place the block after the current block, if possible, or else at
664 // the end of the function.
665 if (CurBB && CurBB->getParent())
666 CurFn->insert(std::next(CurBB->getIterator()), BB);
667 else
668 CurFn->insert(CurFn->end(), BB);
669 Builder.SetInsertPoint(BB);
670 }
671
EmitBranch(llvm::BasicBlock * Target)672 void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) {
673 // Emit a branch from the current block to the target one if this
674 // was a real block. If this was just a fall-through block after a
675 // terminator, don't emit it.
676 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
677
678 if (!CurBB || CurBB->getTerminator()) {
679 // If there is no insert point or the previous block is already
680 // terminated, don't touch it.
681 } else {
682 // Otherwise, create a fall-through branch.
683 Builder.CreateBr(Target);
684 }
685
686 Builder.ClearInsertionPoint();
687 }
688
EmitBlockAfterUses(llvm::BasicBlock * block)689 void CodeGenFunction::EmitBlockAfterUses(llvm::BasicBlock *block) {
690 bool inserted = false;
691 for (llvm::User *u : block->users()) {
692 if (llvm::Instruction *insn = dyn_cast<llvm::Instruction>(u)) {
693 CurFn->insert(std::next(insn->getParent()->getIterator()), block);
694 inserted = true;
695 break;
696 }
697 }
698
699 if (!inserted)
700 CurFn->insert(CurFn->end(), block);
701
702 Builder.SetInsertPoint(block);
703 }
704
705 CodeGenFunction::JumpDest
getJumpDestForLabel(const LabelDecl * D)706 CodeGenFunction::getJumpDestForLabel(const LabelDecl *D) {
707 JumpDest &Dest = LabelMap[D];
708 if (Dest.isValid()) return Dest;
709
710 // Create, but don't insert, the new block.
711 Dest = JumpDest(createBasicBlock(D->getName()),
712 EHScopeStack::stable_iterator::invalid(),
713 NextCleanupDestIndex++);
714 return Dest;
715 }
716
EmitLabel(const LabelDecl * D)717 void CodeGenFunction::EmitLabel(const LabelDecl *D) {
718 // Add this label to the current lexical scope if we're within any
719 // normal cleanups. Jumps "in" to this label --- when permitted by
720 // the language --- may need to be routed around such cleanups.
721 if (EHStack.hasNormalCleanups() && CurLexicalScope)
722 CurLexicalScope->addLabel(D);
723
724 JumpDest &Dest = LabelMap[D];
725
726 // If we didn't need a forward reference to this label, just go
727 // ahead and create a destination at the current scope.
728 if (!Dest.isValid()) {
729 Dest = getJumpDestInCurrentScope(D->getName());
730
731 // Otherwise, we need to give this label a target depth and remove
732 // it from the branch-fixups list.
733 } else {
734 assert(!Dest.getScopeDepth().isValid() && "already emitted label!");
735 Dest.setScopeDepth(EHStack.stable_begin());
736 ResolveBranchFixups(Dest.getBlock());
737 }
738
739 EmitBlock(Dest.getBlock());
740
741 // Emit debug info for labels.
742 if (CGDebugInfo *DI = getDebugInfo()) {
743 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) {
744 DI->setLocation(D->getLocation());
745 DI->EmitLabel(D, Builder);
746 }
747 }
748
749 incrementProfileCounter(D->getStmt());
750 }
751
752 /// Change the cleanup scope of the labels in this lexical scope to
753 /// match the scope of the enclosing context.
rescopeLabels()754 void CodeGenFunction::LexicalScope::rescopeLabels() {
755 assert(!Labels.empty());
756 EHScopeStack::stable_iterator innermostScope
757 = CGF.EHStack.getInnermostNormalCleanup();
758
759 // Change the scope depth of all the labels.
760 for (const LabelDecl *Label : Labels) {
761 assert(CGF.LabelMap.count(Label));
762 JumpDest &dest = CGF.LabelMap.find(Label)->second;
763 assert(dest.getScopeDepth().isValid());
764 assert(innermostScope.encloses(dest.getScopeDepth()));
765 dest.setScopeDepth(innermostScope);
766 }
767
768 // Reparent the labels if the new scope also has cleanups.
769 if (innermostScope != EHScopeStack::stable_end() && ParentScope) {
770 ParentScope->Labels.append(Labels.begin(), Labels.end());
771 }
772 }
773
774
EmitLabelStmt(const LabelStmt & S)775 void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) {
776 EmitLabel(S.getDecl());
777
778 // IsEHa - emit eha.scope.begin if it's a side entry of a scope
779 if (getLangOpts().EHAsynch && S.isSideEntry())
780 EmitSehCppScopeBegin();
781
782 EmitStmt(S.getSubStmt());
783 }
784
EmitAttributedStmt(const AttributedStmt & S)785 void CodeGenFunction::EmitAttributedStmt(const AttributedStmt &S) {
786 bool nomerge = false;
787 bool noinline = false;
788 bool alwaysinline = false;
789 bool noconvergent = false;
790 HLSLControlFlowHintAttr::Spelling flattenOrBranch =
791 HLSLControlFlowHintAttr::SpellingNotCalculated;
792 const CallExpr *musttail = nullptr;
793 const AtomicAttr *AA = nullptr;
794
795 for (const auto *A : S.getAttrs()) {
796 switch (A->getKind()) {
797 default:
798 break;
799 case attr::NoMerge:
800 nomerge = true;
801 break;
802 case attr::NoInline:
803 noinline = true;
804 break;
805 case attr::AlwaysInline:
806 alwaysinline = true;
807 break;
808 case attr::NoConvergent:
809 noconvergent = true;
810 break;
811 case attr::MustTail: {
812 const Stmt *Sub = S.getSubStmt();
813 const ReturnStmt *R = cast<ReturnStmt>(Sub);
814 musttail = cast<CallExpr>(R->getRetValue()->IgnoreParens());
815 } break;
816 case attr::CXXAssume: {
817 const Expr *Assumption = cast<CXXAssumeAttr>(A)->getAssumption();
818 if (getLangOpts().CXXAssumptions && Builder.GetInsertBlock() &&
819 !Assumption->HasSideEffects(getContext())) {
820 llvm::Value *AssumptionVal = EmitCheckedArgForAssume(Assumption);
821 Builder.CreateAssumption(AssumptionVal);
822 }
823 } break;
824 case attr::Atomic:
825 AA = cast<AtomicAttr>(A);
826 break;
827 case attr::HLSLControlFlowHint: {
828 flattenOrBranch = cast<HLSLControlFlowHintAttr>(A)->getSemanticSpelling();
829 } break;
830 }
831 }
832 SaveAndRestore save_nomerge(InNoMergeAttributedStmt, nomerge);
833 SaveAndRestore save_noinline(InNoInlineAttributedStmt, noinline);
834 SaveAndRestore save_alwaysinline(InAlwaysInlineAttributedStmt, alwaysinline);
835 SaveAndRestore save_noconvergent(InNoConvergentAttributedStmt, noconvergent);
836 SaveAndRestore save_musttail(MustTailCall, musttail);
837 SaveAndRestore save_flattenOrBranch(HLSLControlFlowAttr, flattenOrBranch);
838 CGAtomicOptionsRAII AORAII(CGM, AA);
839 EmitStmt(S.getSubStmt(), S.getAttrs());
840 }
841
EmitGotoStmt(const GotoStmt & S)842 void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
843 // If this code is reachable then emit a stop point (if generating
844 // debug info). We have to do this ourselves because we are on the
845 // "simple" statement path.
846 if (HaveInsertPoint())
847 EmitStopPoint(&S);
848
849 ApplyAtomGroup Grp(getDebugInfo());
850 EmitBranchThroughCleanup(getJumpDestForLabel(S.getLabel()));
851 }
852
853
EmitIndirectGotoStmt(const IndirectGotoStmt & S)854 void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
855 ApplyAtomGroup Grp(getDebugInfo());
856 if (const LabelDecl *Target = S.getConstantTarget()) {
857 EmitBranchThroughCleanup(getJumpDestForLabel(Target));
858 return;
859 }
860
861 // Ensure that we have an i8* for our PHI node.
862 llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()),
863 Int8PtrTy, "addr");
864 llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
865
866 // Get the basic block for the indirect goto.
867 llvm::BasicBlock *IndGotoBB = GetIndirectGotoBlock();
868
869 // The first instruction in the block has to be the PHI for the switch dest,
870 // add an entry for this branch.
871 cast<llvm::PHINode>(IndGotoBB->begin())->addIncoming(V, CurBB);
872
873 EmitBranch(IndGotoBB);
874 if (CurBB && CurBB->getTerminator())
875 addInstToCurrentSourceAtom(CurBB->getTerminator(), nullptr);
876 }
877
EmitIfStmt(const IfStmt & S)878 void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
879 const Stmt *Else = S.getElse();
880
881 // The else branch of a consteval if statement is always the only branch that
882 // can be runtime evaluated.
883 if (S.isConsteval()) {
884 const Stmt *Executed = S.isNegatedConsteval() ? S.getThen() : Else;
885 if (Executed) {
886 RunCleanupsScope ExecutedScope(*this);
887 EmitStmt(Executed);
888 }
889 return;
890 }
891
892 // C99 6.8.4.1: The first substatement is executed if the expression compares
893 // unequal to 0. The condition must be a scalar type.
894 LexicalScope ConditionScope(*this, S.getCond()->getSourceRange());
895 ApplyDebugLocation DL(*this, S.getCond());
896
897 if (S.getInit())
898 EmitStmt(S.getInit());
899
900 if (S.getConditionVariable())
901 EmitDecl(*S.getConditionVariable());
902
903 // If the condition constant folds and can be elided, try to avoid emitting
904 // the condition and the dead arm of the if/else.
905 bool CondConstant;
906 if (ConstantFoldsToSimpleInteger(S.getCond(), CondConstant,
907 S.isConstexpr())) {
908 // Figure out which block (then or else) is executed.
909 const Stmt *Executed = S.getThen();
910 const Stmt *Skipped = Else;
911 if (!CondConstant) // Condition false?
912 std::swap(Executed, Skipped);
913
914 // If the skipped block has no labels in it, just emit the executed block.
915 // This avoids emitting dead code and simplifies the CFG substantially.
916 if (S.isConstexpr() || !ContainsLabel(Skipped)) {
917 if (CondConstant)
918 incrementProfileCounter(&S);
919 if (Executed) {
920 MaybeEmitDeferredVarDeclInit(S.getConditionVariable());
921 RunCleanupsScope ExecutedScope(*this);
922 EmitStmt(Executed);
923 }
924 PGO->markStmtMaybeUsed(Skipped);
925 return;
926 }
927 }
928
929 // Otherwise, the condition did not fold, or we couldn't elide it. Just emit
930 // the conditional branch.
931 llvm::BasicBlock *ThenBlock = createBasicBlock("if.then");
932 llvm::BasicBlock *ContBlock = createBasicBlock("if.end");
933 llvm::BasicBlock *ElseBlock = ContBlock;
934 if (Else)
935 ElseBlock = createBasicBlock("if.else");
936
937 // Prefer the PGO based weights over the likelihood attribute.
938 // When the build isn't optimized the metadata isn't used, so don't generate
939 // it.
940 // Also, differentiate between disabled PGO and a never executed branch with
941 // PGO. Assuming PGO is in use:
942 // - we want to ignore the [[likely]] attribute if the branch is never
943 // executed,
944 // - assuming the profile is poor, preserving the attribute may still be
945 // beneficial.
946 // As an approximation, preserve the attribute only if both the branch and the
947 // parent context were not executed.
948 Stmt::Likelihood LH = Stmt::LH_None;
949 uint64_t ThenCount = getProfileCount(S.getThen());
950 if (!ThenCount && !getCurrentProfileCount() &&
951 CGM.getCodeGenOpts().OptimizationLevel)
952 LH = Stmt::getLikelihood(S.getThen(), Else);
953
954 // When measuring MC/DC, always fully evaluate the condition up front using
955 // EvaluateExprAsBool() so that the test vector bitmap can be updated prior to
956 // executing the body of the if.then or if.else. This is useful for when
957 // there is a 'return' within the body, but this is particularly beneficial
958 // when one if-stmt is nested within another if-stmt so that all of the MC/DC
959 // updates are kept linear and consistent.
960 if (!CGM.getCodeGenOpts().MCDCCoverage) {
961 EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock, ThenCount, LH,
962 /*ConditionalOp=*/nullptr,
963 /*ConditionalDecl=*/S.getConditionVariable());
964 } else {
965 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
966 MaybeEmitDeferredVarDeclInit(S.getConditionVariable());
967 Builder.CreateCondBr(BoolCondVal, ThenBlock, ElseBlock);
968 }
969
970 // Emit the 'then' code.
971 EmitBlock(ThenBlock);
972 if (llvm::EnableSingleByteCoverage)
973 incrementProfileCounter(S.getThen());
974 else
975 incrementProfileCounter(&S);
976 {
977 RunCleanupsScope ThenScope(*this);
978 EmitStmt(S.getThen());
979 }
980 EmitBranch(ContBlock);
981
982 // Emit the 'else' code if present.
983 if (Else) {
984 {
985 // There is no need to emit line number for an unconditional branch.
986 auto NL = ApplyDebugLocation::CreateEmpty(*this);
987 EmitBlock(ElseBlock);
988 }
989 // When single byte coverage mode is enabled, add a counter to else block.
990 if (llvm::EnableSingleByteCoverage)
991 incrementProfileCounter(Else);
992 {
993 RunCleanupsScope ElseScope(*this);
994 EmitStmt(Else);
995 }
996 {
997 // There is no need to emit line number for an unconditional branch.
998 auto NL = ApplyDebugLocation::CreateEmpty(*this);
999 EmitBranch(ContBlock);
1000 }
1001 }
1002
1003 // Emit the continuation block for code after the if.
1004 EmitBlock(ContBlock, true);
1005
1006 // When single byte coverage mode is enabled, add a counter to continuation
1007 // block.
1008 if (llvm::EnableSingleByteCoverage)
1009 incrementProfileCounter(&S);
1010 }
1011
checkIfLoopMustProgress(const Expr * ControllingExpression,bool HasEmptyBody)1012 bool CodeGenFunction::checkIfLoopMustProgress(const Expr *ControllingExpression,
1013 bool HasEmptyBody) {
1014 if (CGM.getCodeGenOpts().getFiniteLoops() ==
1015 CodeGenOptions::FiniteLoopsKind::Never)
1016 return false;
1017
1018 // Now apply rules for plain C (see 6.8.5.6 in C11).
1019 // Loops with constant conditions do not have to make progress in any C
1020 // version.
1021 // As an extension, we consisider loops whose constant expression
1022 // can be constant-folded.
1023 Expr::EvalResult Result;
1024 bool CondIsConstInt =
1025 !ControllingExpression ||
1026 (ControllingExpression->EvaluateAsInt(Result, getContext()) &&
1027 Result.Val.isInt());
1028
1029 bool CondIsTrue = CondIsConstInt && (!ControllingExpression ||
1030 Result.Val.getInt().getBoolValue());
1031
1032 // Loops with non-constant conditions must make progress in C11 and later.
1033 if (getLangOpts().C11 && !CondIsConstInt)
1034 return true;
1035
1036 // [C++26][intro.progress] (DR)
1037 // The implementation may assume that any thread will eventually do one of the
1038 // following:
1039 // [...]
1040 // - continue execution of a trivial infinite loop ([stmt.iter.general]).
1041 if (CGM.getCodeGenOpts().getFiniteLoops() ==
1042 CodeGenOptions::FiniteLoopsKind::Always ||
1043 getLangOpts().CPlusPlus11) {
1044 if (HasEmptyBody && CondIsTrue) {
1045 CurFn->removeFnAttr(llvm::Attribute::MustProgress);
1046 return false;
1047 }
1048 return true;
1049 }
1050 return false;
1051 }
1052
1053 // [C++26][stmt.iter.general] (DR)
1054 // A trivially empty iteration statement is an iteration statement matching one
1055 // of the following forms:
1056 // - while ( expression ) ;
1057 // - while ( expression ) { }
1058 // - do ; while ( expression ) ;
1059 // - do { } while ( expression ) ;
1060 // - for ( init-statement expression(opt); ) ;
1061 // - for ( init-statement expression(opt); ) { }
hasEmptyLoopBody(const LoopStmt & S)1062 template <typename LoopStmt> static bool hasEmptyLoopBody(const LoopStmt &S) {
1063 if constexpr (std::is_same_v<LoopStmt, ForStmt>) {
1064 if (S.getInc())
1065 return false;
1066 }
1067 const Stmt *Body = S.getBody();
1068 if (!Body || isa<NullStmt>(Body))
1069 return true;
1070 if (const CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body))
1071 return Compound->body_empty();
1072 return false;
1073 }
1074
EmitWhileStmt(const WhileStmt & S,ArrayRef<const Attr * > WhileAttrs)1075 void CodeGenFunction::EmitWhileStmt(const WhileStmt &S,
1076 ArrayRef<const Attr *> WhileAttrs) {
1077 // Emit the header for the loop, which will also become
1078 // the continue target.
1079 JumpDest LoopHeader = getJumpDestInCurrentScope("while.cond");
1080 EmitBlock(LoopHeader.getBlock());
1081
1082 if (CGM.shouldEmitConvergenceTokens())
1083 ConvergenceTokenStack.push_back(
1084 emitConvergenceLoopToken(LoopHeader.getBlock()));
1085
1086 // Create an exit block for when the condition fails, which will
1087 // also become the break target.
1088 JumpDest LoopExit = getJumpDestInCurrentScope("while.end");
1089
1090 // Store the blocks to use for break and continue.
1091 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopHeader));
1092
1093 // C++ [stmt.while]p2:
1094 // When the condition of a while statement is a declaration, the
1095 // scope of the variable that is declared extends from its point
1096 // of declaration (3.3.2) to the end of the while statement.
1097 // [...]
1098 // The object created in a condition is destroyed and created
1099 // with each iteration of the loop.
1100 RunCleanupsScope ConditionScope(*this);
1101
1102 if (S.getConditionVariable())
1103 EmitDecl(*S.getConditionVariable());
1104
1105 // Evaluate the conditional in the while header. C99 6.8.5.1: The
1106 // evaluation of the controlling expression takes place before each
1107 // execution of the loop body.
1108 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
1109
1110 MaybeEmitDeferredVarDeclInit(S.getConditionVariable());
1111
1112 // while(1) is common, avoid extra exit blocks. Be sure
1113 // to correctly handle break/continue though.
1114 llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal);
1115 bool EmitBoolCondBranch = !C || !C->isOne();
1116 const SourceRange &R = S.getSourceRange();
1117 LoopStack.push(LoopHeader.getBlock(), CGM.getContext(), CGM.getCodeGenOpts(),
1118 WhileAttrs, SourceLocToDebugLoc(R.getBegin()),
1119 SourceLocToDebugLoc(R.getEnd()),
1120 checkIfLoopMustProgress(S.getCond(), hasEmptyLoopBody(S)));
1121
1122 // When single byte coverage mode is enabled, add a counter to loop condition.
1123 if (llvm::EnableSingleByteCoverage)
1124 incrementProfileCounter(S.getCond());
1125
1126 // As long as the condition is true, go to the loop body.
1127 llvm::BasicBlock *LoopBody = createBasicBlock("while.body");
1128 if (EmitBoolCondBranch) {
1129 llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
1130 if (ConditionScope.requiresCleanups())
1131 ExitBlock = createBasicBlock("while.exit");
1132 llvm::MDNode *Weights =
1133 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()));
1134 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel)
1135 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic(
1136 BoolCondVal, Stmt::getLikelihood(S.getBody()));
1137 auto *I = Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock, Weights);
1138 // Key Instructions: Emit the condition and branch as separate source
1139 // location atoms otherwise we may omit a step onto the loop condition in
1140 // favour of the `while` keyword.
1141 // FIXME: We could have the branch as the backup location for the condition,
1142 // which would probably be a better experience. Explore this later.
1143 if (auto *CondI = dyn_cast<llvm::Instruction>(BoolCondVal))
1144 addInstToNewSourceAtom(CondI, nullptr);
1145 addInstToNewSourceAtom(I, nullptr);
1146
1147 if (ExitBlock != LoopExit.getBlock()) {
1148 EmitBlock(ExitBlock);
1149 EmitBranchThroughCleanup(LoopExit);
1150 }
1151 } else if (const Attr *A = Stmt::getLikelihoodAttr(S.getBody())) {
1152 CGM.getDiags().Report(A->getLocation(),
1153 diag::warn_attribute_has_no_effect_on_infinite_loop)
1154 << A << A->getRange();
1155 CGM.getDiags().Report(
1156 S.getWhileLoc(),
1157 diag::note_attribute_has_no_effect_on_infinite_loop_here)
1158 << SourceRange(S.getWhileLoc(), S.getRParenLoc());
1159 }
1160
1161 // Emit the loop body. We have to emit this in a cleanup scope
1162 // because it might be a singleton DeclStmt.
1163 {
1164 RunCleanupsScope BodyScope(*this);
1165 EmitBlock(LoopBody);
1166 // When single byte coverage mode is enabled, add a counter to the body.
1167 if (llvm::EnableSingleByteCoverage)
1168 incrementProfileCounter(S.getBody());
1169 else
1170 incrementProfileCounter(&S);
1171 EmitStmt(S.getBody());
1172 }
1173
1174 BreakContinueStack.pop_back();
1175
1176 // Immediately force cleanup.
1177 ConditionScope.ForceCleanup();
1178
1179 EmitStopPoint(&S);
1180 // Branch to the loop header again.
1181 EmitBranch(LoopHeader.getBlock());
1182
1183 LoopStack.pop();
1184
1185 // Emit the exit block.
1186 EmitBlock(LoopExit.getBlock(), true);
1187
1188 // The LoopHeader typically is just a branch if we skipped emitting
1189 // a branch, try to erase it.
1190 if (!EmitBoolCondBranch)
1191 SimplifyForwardingBlocks(LoopHeader.getBlock());
1192
1193 // When single byte coverage mode is enabled, add a counter to continuation
1194 // block.
1195 if (llvm::EnableSingleByteCoverage)
1196 incrementProfileCounter(&S);
1197
1198 if (CGM.shouldEmitConvergenceTokens())
1199 ConvergenceTokenStack.pop_back();
1200 }
1201
EmitDoStmt(const DoStmt & S,ArrayRef<const Attr * > DoAttrs)1202 void CodeGenFunction::EmitDoStmt(const DoStmt &S,
1203 ArrayRef<const Attr *> DoAttrs) {
1204 JumpDest LoopExit = getJumpDestInCurrentScope("do.end");
1205 JumpDest LoopCond = getJumpDestInCurrentScope("do.cond");
1206
1207 uint64_t ParentCount = getCurrentProfileCount();
1208
1209 // Store the blocks to use for break and continue.
1210 BreakContinueStack.push_back(BreakContinue(LoopExit, LoopCond));
1211
1212 // Emit the body of the loop.
1213 llvm::BasicBlock *LoopBody = createBasicBlock("do.body");
1214
1215 if (llvm::EnableSingleByteCoverage)
1216 EmitBlockWithFallThrough(LoopBody, S.getBody());
1217 else
1218 EmitBlockWithFallThrough(LoopBody, &S);
1219
1220 if (CGM.shouldEmitConvergenceTokens())
1221 ConvergenceTokenStack.push_back(emitConvergenceLoopToken(LoopBody));
1222
1223 {
1224 RunCleanupsScope BodyScope(*this);
1225 EmitStmt(S.getBody());
1226 }
1227
1228 EmitBlock(LoopCond.getBlock());
1229 // When single byte coverage mode is enabled, add a counter to loop condition.
1230 if (llvm::EnableSingleByteCoverage)
1231 incrementProfileCounter(S.getCond());
1232
1233 // C99 6.8.5.2: "The evaluation of the controlling expression takes place
1234 // after each execution of the loop body."
1235
1236 // Evaluate the conditional in the while header.
1237 // C99 6.8.5p2/p4: The first substatement is executed if the expression
1238 // compares unequal to 0. The condition must be a scalar type.
1239 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
1240
1241 BreakContinueStack.pop_back();
1242
1243 // "do {} while (0)" is common in macros, avoid extra blocks. Be sure
1244 // to correctly handle break/continue though.
1245 llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal);
1246 bool EmitBoolCondBranch = !C || !C->isZero();
1247
1248 const SourceRange &R = S.getSourceRange();
1249 LoopStack.push(LoopBody, CGM.getContext(), CGM.getCodeGenOpts(), DoAttrs,
1250 SourceLocToDebugLoc(R.getBegin()),
1251 SourceLocToDebugLoc(R.getEnd()),
1252 checkIfLoopMustProgress(S.getCond(), hasEmptyLoopBody(S)));
1253
1254 // As long as the condition is true, iterate the loop.
1255 if (EmitBoolCondBranch) {
1256 uint64_t BackedgeCount = getProfileCount(S.getBody()) - ParentCount;
1257 auto *I = Builder.CreateCondBr(
1258 BoolCondVal, LoopBody, LoopExit.getBlock(),
1259 createProfileWeightsForLoop(S.getCond(), BackedgeCount));
1260
1261 // Key Instructions: Emit the condition and branch as separate source
1262 // location atoms otherwise we may omit a step onto the loop condition in
1263 // favour of the closing brace.
1264 // FIXME: We could have the branch as the backup location for the condition,
1265 // which would probably be a better experience (no jumping to the brace).
1266 if (auto *CondI = dyn_cast<llvm::Instruction>(BoolCondVal))
1267 addInstToNewSourceAtom(CondI, nullptr);
1268 addInstToNewSourceAtom(I, nullptr);
1269 }
1270
1271 LoopStack.pop();
1272
1273 // Emit the exit block.
1274 EmitBlock(LoopExit.getBlock());
1275
1276 // The DoCond block typically is just a branch if we skipped
1277 // emitting a branch, try to erase it.
1278 if (!EmitBoolCondBranch)
1279 SimplifyForwardingBlocks(LoopCond.getBlock());
1280
1281 // When single byte coverage mode is enabled, add a counter to continuation
1282 // block.
1283 if (llvm::EnableSingleByteCoverage)
1284 incrementProfileCounter(&S);
1285
1286 if (CGM.shouldEmitConvergenceTokens())
1287 ConvergenceTokenStack.pop_back();
1288 }
1289
EmitForStmt(const ForStmt & S,ArrayRef<const Attr * > ForAttrs)1290 void CodeGenFunction::EmitForStmt(const ForStmt &S,
1291 ArrayRef<const Attr *> ForAttrs) {
1292 JumpDest LoopExit = getJumpDestInCurrentScope("for.end");
1293
1294 LexicalScope ForScope(*this, S.getSourceRange());
1295
1296 // Evaluate the first part before the loop.
1297 if (S.getInit())
1298 EmitStmt(S.getInit());
1299
1300 // Start the loop with a block that tests the condition.
1301 // If there's an increment, the continue scope will be overwritten
1302 // later.
1303 JumpDest CondDest = getJumpDestInCurrentScope("for.cond");
1304 llvm::BasicBlock *CondBlock = CondDest.getBlock();
1305 EmitBlock(CondBlock);
1306
1307 if (CGM.shouldEmitConvergenceTokens())
1308 ConvergenceTokenStack.push_back(emitConvergenceLoopToken(CondBlock));
1309
1310 const SourceRange &R = S.getSourceRange();
1311 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs,
1312 SourceLocToDebugLoc(R.getBegin()),
1313 SourceLocToDebugLoc(R.getEnd()),
1314 checkIfLoopMustProgress(S.getCond(), hasEmptyLoopBody(S)));
1315
1316 // Create a cleanup scope for the condition variable cleanups.
1317 LexicalScope ConditionScope(*this, S.getSourceRange());
1318
1319 // If the for loop doesn't have an increment we can just use the condition as
1320 // the continue block. Otherwise, if there is no condition variable, we can
1321 // form the continue block now. If there is a condition variable, we can't
1322 // form the continue block until after we've emitted the condition, because
1323 // the condition is in scope in the increment, but Sema's jump diagnostics
1324 // ensure that there are no continues from the condition variable that jump
1325 // to the loop increment.
1326 JumpDest Continue;
1327 if (!S.getInc())
1328 Continue = CondDest;
1329 else if (!S.getConditionVariable())
1330 Continue = getJumpDestInCurrentScope("for.inc");
1331 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
1332
1333 if (S.getCond()) {
1334 // If the for statement has a condition scope, emit the local variable
1335 // declaration.
1336 if (S.getConditionVariable()) {
1337 EmitDecl(*S.getConditionVariable());
1338
1339 // We have entered the condition variable's scope, so we're now able to
1340 // jump to the continue block.
1341 Continue = S.getInc() ? getJumpDestInCurrentScope("for.inc") : CondDest;
1342 BreakContinueStack.back().ContinueBlock = Continue;
1343 }
1344
1345 // When single byte coverage mode is enabled, add a counter to loop
1346 // condition.
1347 if (llvm::EnableSingleByteCoverage)
1348 incrementProfileCounter(S.getCond());
1349
1350 llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
1351 // If there are any cleanups between here and the loop-exit scope,
1352 // create a block to stage a loop exit along.
1353 if (ForScope.requiresCleanups())
1354 ExitBlock = createBasicBlock("for.cond.cleanup");
1355
1356 // As long as the condition is true, iterate the loop.
1357 llvm::BasicBlock *ForBody = createBasicBlock("for.body");
1358
1359 // C99 6.8.5p2/p4: The first substatement is executed if the expression
1360 // compares unequal to 0. The condition must be a scalar type.
1361 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
1362
1363 MaybeEmitDeferredVarDeclInit(S.getConditionVariable());
1364
1365 llvm::MDNode *Weights =
1366 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()));
1367 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel)
1368 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic(
1369 BoolCondVal, Stmt::getLikelihood(S.getBody()));
1370
1371 auto *I = Builder.CreateCondBr(BoolCondVal, ForBody, ExitBlock, Weights);
1372 // Key Instructions: Emit the condition and branch as separate atoms to
1373 // match existing loop stepping behaviour. FIXME: We could have the branch
1374 // as the backup location for the condition, which would probably be a
1375 // better experience (no jumping to the brace).
1376 if (auto *CondI = dyn_cast<llvm::Instruction>(BoolCondVal))
1377 addInstToNewSourceAtom(CondI, nullptr);
1378 addInstToNewSourceAtom(I, nullptr);
1379
1380 if (ExitBlock != LoopExit.getBlock()) {
1381 EmitBlock(ExitBlock);
1382 EmitBranchThroughCleanup(LoopExit);
1383 }
1384
1385 EmitBlock(ForBody);
1386 } else {
1387 // Treat it as a non-zero constant. Don't even create a new block for the
1388 // body, just fall into it.
1389 }
1390
1391 // When single byte coverage mode is enabled, add a counter to the body.
1392 if (llvm::EnableSingleByteCoverage)
1393 incrementProfileCounter(S.getBody());
1394 else
1395 incrementProfileCounter(&S);
1396 {
1397 // Create a separate cleanup scope for the body, in case it is not
1398 // a compound statement.
1399 RunCleanupsScope BodyScope(*this);
1400 EmitStmt(S.getBody());
1401 }
1402
1403 // The last block in the loop's body (which unconditionally branches to the
1404 // `inc` block if there is one).
1405 auto *FinalBodyBB = Builder.GetInsertBlock();
1406
1407 // If there is an increment, emit it next.
1408 if (S.getInc()) {
1409 EmitBlock(Continue.getBlock());
1410 EmitStmt(S.getInc());
1411 if (llvm::EnableSingleByteCoverage)
1412 incrementProfileCounter(S.getInc());
1413 }
1414
1415 BreakContinueStack.pop_back();
1416
1417 ConditionScope.ForceCleanup();
1418
1419 EmitStopPoint(&S);
1420 EmitBranch(CondBlock);
1421
1422 ForScope.ForceCleanup();
1423
1424 LoopStack.pop();
1425
1426 // Emit the fall-through block.
1427 EmitBlock(LoopExit.getBlock(), true);
1428
1429 // When single byte coverage mode is enabled, add a counter to continuation
1430 // block.
1431 if (llvm::EnableSingleByteCoverage)
1432 incrementProfileCounter(&S);
1433
1434 if (CGM.shouldEmitConvergenceTokens())
1435 ConvergenceTokenStack.pop_back();
1436
1437 if (FinalBodyBB) {
1438 // Key Instructions: We want the for closing brace to be step-able on to
1439 // match existing behaviour.
1440 addInstToNewSourceAtom(FinalBodyBB->getTerminator(), nullptr);
1441 }
1442 }
1443
1444 void
EmitCXXForRangeStmt(const CXXForRangeStmt & S,ArrayRef<const Attr * > ForAttrs)1445 CodeGenFunction::EmitCXXForRangeStmt(const CXXForRangeStmt &S,
1446 ArrayRef<const Attr *> ForAttrs) {
1447 JumpDest LoopExit = getJumpDestInCurrentScope("for.end");
1448
1449 LexicalScope ForScope(*this, S.getSourceRange());
1450
1451 // Evaluate the first pieces before the loop.
1452 if (S.getInit())
1453 EmitStmt(S.getInit());
1454 EmitStmt(S.getRangeStmt());
1455 EmitStmt(S.getBeginStmt());
1456 EmitStmt(S.getEndStmt());
1457
1458 // Start the loop with a block that tests the condition.
1459 // If there's an increment, the continue scope will be overwritten
1460 // later.
1461 llvm::BasicBlock *CondBlock = createBasicBlock("for.cond");
1462 EmitBlock(CondBlock);
1463
1464 if (CGM.shouldEmitConvergenceTokens())
1465 ConvergenceTokenStack.push_back(emitConvergenceLoopToken(CondBlock));
1466
1467 const SourceRange &R = S.getSourceRange();
1468 LoopStack.push(CondBlock, CGM.getContext(), CGM.getCodeGenOpts(), ForAttrs,
1469 SourceLocToDebugLoc(R.getBegin()),
1470 SourceLocToDebugLoc(R.getEnd()));
1471
1472 // If there are any cleanups between here and the loop-exit scope,
1473 // create a block to stage a loop exit along.
1474 llvm::BasicBlock *ExitBlock = LoopExit.getBlock();
1475 if (ForScope.requiresCleanups())
1476 ExitBlock = createBasicBlock("for.cond.cleanup");
1477
1478 // The loop body, consisting of the specified body and the loop variable.
1479 llvm::BasicBlock *ForBody = createBasicBlock("for.body");
1480
1481 // The body is executed if the expression, contextually converted
1482 // to bool, is true.
1483 llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
1484 llvm::MDNode *Weights =
1485 createProfileWeightsForLoop(S.getCond(), getProfileCount(S.getBody()));
1486 if (!Weights && CGM.getCodeGenOpts().OptimizationLevel)
1487 BoolCondVal = emitCondLikelihoodViaExpectIntrinsic(
1488 BoolCondVal, Stmt::getLikelihood(S.getBody()));
1489 auto *I = Builder.CreateCondBr(BoolCondVal, ForBody, ExitBlock, Weights);
1490 // Key Instructions: Emit the condition and branch as separate atoms to
1491 // match existing loop stepping behaviour. FIXME: We could have the branch as
1492 // the backup location for the condition, which would probably be a better
1493 // experience.
1494 if (auto *CondI = dyn_cast<llvm::Instruction>(BoolCondVal))
1495 addInstToNewSourceAtom(CondI, nullptr);
1496 addInstToNewSourceAtom(I, nullptr);
1497
1498 if (ExitBlock != LoopExit.getBlock()) {
1499 EmitBlock(ExitBlock);
1500 EmitBranchThroughCleanup(LoopExit);
1501 }
1502
1503 EmitBlock(ForBody);
1504 if (llvm::EnableSingleByteCoverage)
1505 incrementProfileCounter(S.getBody());
1506 else
1507 incrementProfileCounter(&S);
1508
1509 // Create a block for the increment. In case of a 'continue', we jump there.
1510 JumpDest Continue = getJumpDestInCurrentScope("for.inc");
1511
1512 // Store the blocks to use for break and continue.
1513 BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
1514
1515 {
1516 // Create a separate cleanup scope for the loop variable and body.
1517 LexicalScope BodyScope(*this, S.getSourceRange());
1518 EmitStmt(S.getLoopVarStmt());
1519 EmitStmt(S.getBody());
1520 }
1521 // The last block in the loop's body (which unconditionally branches to the
1522 // `inc` block if there is one).
1523 auto *FinalBodyBB = Builder.GetInsertBlock();
1524
1525 EmitStopPoint(&S);
1526 // If there is an increment, emit it next.
1527 EmitBlock(Continue.getBlock());
1528 EmitStmt(S.getInc());
1529
1530 BreakContinueStack.pop_back();
1531
1532 EmitBranch(CondBlock);
1533
1534 ForScope.ForceCleanup();
1535
1536 LoopStack.pop();
1537
1538 // Emit the fall-through block.
1539 EmitBlock(LoopExit.getBlock(), true);
1540
1541 // When single byte coverage mode is enabled, add a counter to continuation
1542 // block.
1543 if (llvm::EnableSingleByteCoverage)
1544 incrementProfileCounter(&S);
1545
1546 if (CGM.shouldEmitConvergenceTokens())
1547 ConvergenceTokenStack.pop_back();
1548
1549 if (FinalBodyBB) {
1550 // We want the for closing brace to be step-able on to match existing
1551 // behaviour.
1552 addInstToNewSourceAtom(FinalBodyBB->getTerminator(), nullptr);
1553 }
1554 }
1555
EmitReturnOfRValue(RValue RV,QualType Ty)1556 void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) {
1557 if (RV.isScalar()) {
1558 Builder.CreateStore(RV.getScalarVal(), ReturnValue);
1559 } else if (RV.isAggregate()) {
1560 LValue Dest = MakeAddrLValue(ReturnValue, Ty);
1561 LValue Src = MakeAddrLValue(RV.getAggregateAddress(), Ty);
1562 EmitAggregateCopy(Dest, Src, Ty, getOverlapForReturnValue());
1563 } else {
1564 EmitStoreOfComplex(RV.getComplexVal(), MakeAddrLValue(ReturnValue, Ty),
1565 /*init*/ true);
1566 }
1567 EmitBranchThroughCleanup(ReturnBlock);
1568 }
1569
1570 namespace {
1571 // RAII struct used to save and restore a return statment's result expression.
1572 struct SaveRetExprRAII {
SaveRetExprRAII__anon725605700111::SaveRetExprRAII1573 SaveRetExprRAII(const Expr *RetExpr, CodeGenFunction &CGF)
1574 : OldRetExpr(CGF.RetExpr), CGF(CGF) {
1575 CGF.RetExpr = RetExpr;
1576 }
~SaveRetExprRAII__anon725605700111::SaveRetExprRAII1577 ~SaveRetExprRAII() { CGF.RetExpr = OldRetExpr; }
1578 const Expr *OldRetExpr;
1579 CodeGenFunction &CGF;
1580 };
1581 } // namespace
1582
1583 /// Determine if the given call uses the swiftasync calling convention.
isSwiftAsyncCallee(const CallExpr * CE)1584 static bool isSwiftAsyncCallee(const CallExpr *CE) {
1585 auto calleeQualType = CE->getCallee()->getType();
1586 const FunctionType *calleeType = nullptr;
1587 if (calleeQualType->isFunctionPointerType() ||
1588 calleeQualType->isFunctionReferenceType() ||
1589 calleeQualType->isBlockPointerType() ||
1590 calleeQualType->isMemberFunctionPointerType()) {
1591 calleeType = calleeQualType->getPointeeType()->castAs<FunctionType>();
1592 } else if (auto *ty = dyn_cast<FunctionType>(calleeQualType)) {
1593 calleeType = ty;
1594 } else if (auto CMCE = dyn_cast<CXXMemberCallExpr>(CE)) {
1595 if (auto methodDecl = CMCE->getMethodDecl()) {
1596 // getMethodDecl() doesn't handle member pointers at the moment.
1597 calleeType = methodDecl->getType()->castAs<FunctionType>();
1598 } else {
1599 return false;
1600 }
1601 } else {
1602 return false;
1603 }
1604 return calleeType->getCallConv() == CallingConv::CC_SwiftAsync;
1605 }
1606
1607 /// EmitReturnStmt - Note that due to GCC extensions, this can have an operand
1608 /// if the function returns void, or may be missing one if the function returns
1609 /// non-void. Fun stuff :).
EmitReturnStmt(const ReturnStmt & S)1610 void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) {
1611 ApplyAtomGroup Grp(getDebugInfo());
1612 if (requiresReturnValueCheck()) {
1613 llvm::Constant *SLoc = EmitCheckSourceLocation(S.getBeginLoc());
1614 auto *SLocPtr =
1615 new llvm::GlobalVariable(CGM.getModule(), SLoc->getType(), false,
1616 llvm::GlobalVariable::PrivateLinkage, SLoc);
1617 SLocPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1618 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(SLocPtr);
1619 assert(ReturnLocation.isValid() && "No valid return location");
1620 Builder.CreateStore(SLocPtr, ReturnLocation);
1621 }
1622
1623 // Returning from an outlined SEH helper is UB, and we already warn on it.
1624 if (IsOutlinedSEHHelper) {
1625 Builder.CreateUnreachable();
1626 Builder.ClearInsertionPoint();
1627 }
1628
1629 // Emit the result value, even if unused, to evaluate the side effects.
1630 const Expr *RV = S.getRetValue();
1631
1632 // Record the result expression of the return statement. The recorded
1633 // expression is used to determine whether a block capture's lifetime should
1634 // end at the end of the full expression as opposed to the end of the scope
1635 // enclosing the block expression.
1636 //
1637 // This permits a small, easily-implemented exception to our over-conservative
1638 // rules about not jumping to statements following block literals with
1639 // non-trivial cleanups.
1640 SaveRetExprRAII SaveRetExpr(RV, *this);
1641
1642 RunCleanupsScope cleanupScope(*this);
1643 if (const auto *EWC = dyn_cast_or_null<ExprWithCleanups>(RV))
1644 RV = EWC->getSubExpr();
1645
1646 // If we're in a swiftasynccall function, and the return expression is a
1647 // call to a swiftasynccall function, mark the call as the musttail call.
1648 std::optional<llvm::SaveAndRestore<const CallExpr *>> SaveMustTail;
1649 if (RV && CurFnInfo &&
1650 CurFnInfo->getASTCallingConvention() == CallingConv::CC_SwiftAsync) {
1651 if (auto CE = dyn_cast<CallExpr>(RV)) {
1652 if (isSwiftAsyncCallee(CE)) {
1653 SaveMustTail.emplace(MustTailCall, CE);
1654 }
1655 }
1656 }
1657
1658 // FIXME: Clean this up by using an LValue for ReturnTemp,
1659 // EmitStoreThroughLValue, and EmitAnyExpr.
1660 // Check if the NRVO candidate was not globalized in OpenMP mode.
1661 if (getLangOpts().ElideConstructors && S.getNRVOCandidate() &&
1662 S.getNRVOCandidate()->isNRVOVariable() &&
1663 (!getLangOpts().OpenMP ||
1664 !CGM.getOpenMPRuntime()
1665 .getAddressOfLocalVariable(*this, S.getNRVOCandidate())
1666 .isValid())) {
1667 // Apply the named return value optimization for this return statement,
1668 // which means doing nothing: the appropriate result has already been
1669 // constructed into the NRVO variable.
1670
1671 // If there is an NRVO flag for this variable, set it to 1 into indicate
1672 // that the cleanup code should not destroy the variable.
1673 if (llvm::Value *NRVOFlag = NRVOFlags[S.getNRVOCandidate()])
1674 Builder.CreateFlagStore(Builder.getTrue(), NRVOFlag);
1675 } else if (!ReturnValue.isValid() || (RV && RV->getType()->isVoidType())) {
1676 // Make sure not to return anything, but evaluate the expression
1677 // for side effects.
1678 if (RV) {
1679 EmitAnyExpr(RV);
1680 }
1681 } else if (!RV) {
1682 // Do nothing (return value is left uninitialized)
1683 } else if (FnRetTy->isReferenceType()) {
1684 // If this function returns a reference, take the address of the expression
1685 // rather than the value.
1686 RValue Result = EmitReferenceBindingToExpr(RV);
1687 auto *I = Builder.CreateStore(Result.getScalarVal(), ReturnValue);
1688 addInstToCurrentSourceAtom(I, I->getValueOperand());
1689 } else {
1690 switch (getEvaluationKind(RV->getType())) {
1691 case TEK_Scalar: {
1692 llvm::Value *Ret = EmitScalarExpr(RV);
1693 if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect) {
1694 EmitStoreOfScalar(Ret, MakeAddrLValue(ReturnValue, RV->getType()),
1695 /*isInit*/ true);
1696 } else {
1697 auto *I = Builder.CreateStore(Ret, ReturnValue);
1698 addInstToCurrentSourceAtom(I, I->getValueOperand());
1699 }
1700 break;
1701 }
1702 case TEK_Complex:
1703 EmitComplexExprIntoLValue(RV, MakeAddrLValue(ReturnValue, RV->getType()),
1704 /*isInit*/ true);
1705 break;
1706 case TEK_Aggregate:
1707 EmitAggExpr(RV, AggValueSlot::forAddr(
1708 ReturnValue, Qualifiers(),
1709 AggValueSlot::IsDestructed,
1710 AggValueSlot::DoesNotNeedGCBarriers,
1711 AggValueSlot::IsNotAliased,
1712 getOverlapForReturnValue()));
1713 break;
1714 }
1715 }
1716
1717 ++NumReturnExprs;
1718 if (!RV || RV->isEvaluatable(getContext()))
1719 ++NumSimpleReturnExprs;
1720
1721 cleanupScope.ForceCleanup();
1722 EmitBranchThroughCleanup(ReturnBlock);
1723 }
1724
EmitDeclStmt(const DeclStmt & S)1725 void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) {
1726 // As long as debug info is modeled with instructions, we have to ensure we
1727 // have a place to insert here and write the stop point here.
1728 if (HaveInsertPoint())
1729 EmitStopPoint(&S);
1730
1731 for (const auto *I : S.decls())
1732 EmitDecl(*I, /*EvaluateConditionDecl=*/true);
1733 }
1734
EmitBreakStmt(const BreakStmt & S)1735 void CodeGenFunction::EmitBreakStmt(const BreakStmt &S) {
1736 assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!");
1737
1738 // If this code is reachable then emit a stop point (if generating
1739 // debug info). We have to do this ourselves because we are on the
1740 // "simple" statement path.
1741 if (HaveInsertPoint())
1742 EmitStopPoint(&S);
1743
1744 ApplyAtomGroup Grp(getDebugInfo());
1745 EmitBranchThroughCleanup(BreakContinueStack.back().BreakBlock);
1746 }
1747
EmitContinueStmt(const ContinueStmt & S)1748 void CodeGenFunction::EmitContinueStmt(const ContinueStmt &S) {
1749 assert(!BreakContinueStack.empty() && "continue stmt not in a loop!");
1750
1751 // If this code is reachable then emit a stop point (if generating
1752 // debug info). We have to do this ourselves because we are on the
1753 // "simple" statement path.
1754 if (HaveInsertPoint())
1755 EmitStopPoint(&S);
1756
1757 ApplyAtomGroup Grp(getDebugInfo());
1758 EmitBranchThroughCleanup(BreakContinueStack.back().ContinueBlock);
1759 }
1760
1761 /// EmitCaseStmtRange - If case statement range is not too big then
1762 /// add multiple cases to switch instruction, one for each value within
1763 /// the range. If range is too big then emit "if" condition check.
EmitCaseStmtRange(const CaseStmt & S,ArrayRef<const Attr * > Attrs)1764 void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S,
1765 ArrayRef<const Attr *> Attrs) {
1766 assert(S.getRHS() && "Expected RHS value in CaseStmt");
1767
1768 llvm::APSInt LHS = S.getLHS()->EvaluateKnownConstInt(getContext());
1769 llvm::APSInt RHS = S.getRHS()->EvaluateKnownConstInt(getContext());
1770
1771 // Emit the code for this case. We do this first to make sure it is
1772 // properly chained from our predecessor before generating the
1773 // switch machinery to enter this block.
1774 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb");
1775 EmitBlockWithFallThrough(CaseDest, &S);
1776 EmitStmt(S.getSubStmt());
1777
1778 // If range is empty, do nothing.
1779 if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS))
1780 return;
1781
1782 Stmt::Likelihood LH = Stmt::getLikelihood(Attrs);
1783 llvm::APInt Range = RHS - LHS;
1784 // FIXME: parameters such as this should not be hardcoded.
1785 if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) {
1786 // Range is small enough to add multiple switch instruction cases.
1787 uint64_t Total = getProfileCount(&S);
1788 unsigned NCases = Range.getZExtValue() + 1;
1789 // We only have one region counter for the entire set of cases here, so we
1790 // need to divide the weights evenly between the generated cases, ensuring
1791 // that the total weight is preserved. E.g., a weight of 5 over three cases
1792 // will be distributed as weights of 2, 2, and 1.
1793 uint64_t Weight = Total / NCases, Rem = Total % NCases;
1794 for (unsigned I = 0; I != NCases; ++I) {
1795 if (SwitchWeights)
1796 SwitchWeights->push_back(Weight + (Rem ? 1 : 0));
1797 else if (SwitchLikelihood)
1798 SwitchLikelihood->push_back(LH);
1799
1800 if (Rem)
1801 Rem--;
1802 SwitchInsn->addCase(Builder.getInt(LHS), CaseDest);
1803 ++LHS;
1804 }
1805 return;
1806 }
1807
1808 // The range is too big. Emit "if" condition into a new block,
1809 // making sure to save and restore the current insertion point.
1810 llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock();
1811
1812 // Push this test onto the chain of range checks (which terminates
1813 // in the default basic block). The switch's default will be changed
1814 // to the top of this chain after switch emission is complete.
1815 llvm::BasicBlock *FalseDest = CaseRangeBlock;
1816 CaseRangeBlock = createBasicBlock("sw.caserange");
1817
1818 CurFn->insert(CurFn->end(), CaseRangeBlock);
1819 Builder.SetInsertPoint(CaseRangeBlock);
1820
1821 // Emit range check.
1822 llvm::Value *Diff =
1823 Builder.CreateSub(SwitchInsn->getCondition(), Builder.getInt(LHS));
1824 llvm::Value *Cond =
1825 Builder.CreateICmpULE(Diff, Builder.getInt(Range), "inbounds");
1826
1827 llvm::MDNode *Weights = nullptr;
1828 if (SwitchWeights) {
1829 uint64_t ThisCount = getProfileCount(&S);
1830 uint64_t DefaultCount = (*SwitchWeights)[0];
1831 Weights = createProfileWeights(ThisCount, DefaultCount);
1832
1833 // Since we're chaining the switch default through each large case range, we
1834 // need to update the weight for the default, ie, the first case, to include
1835 // this case.
1836 (*SwitchWeights)[0] += ThisCount;
1837 } else if (SwitchLikelihood)
1838 Cond = emitCondLikelihoodViaExpectIntrinsic(Cond, LH);
1839
1840 Builder.CreateCondBr(Cond, CaseDest, FalseDest, Weights);
1841
1842 // Restore the appropriate insertion point.
1843 if (RestoreBB)
1844 Builder.SetInsertPoint(RestoreBB);
1845 else
1846 Builder.ClearInsertionPoint();
1847 }
1848
EmitCaseStmt(const CaseStmt & S,ArrayRef<const Attr * > Attrs)1849 void CodeGenFunction::EmitCaseStmt(const CaseStmt &S,
1850 ArrayRef<const Attr *> Attrs) {
1851 // If there is no enclosing switch instance that we're aware of, then this
1852 // case statement and its block can be elided. This situation only happens
1853 // when we've constant-folded the switch, are emitting the constant case,
1854 // and part of the constant case includes another case statement. For
1855 // instance: switch (4) { case 4: do { case 5: } while (1); }
1856 if (!SwitchInsn) {
1857 EmitStmt(S.getSubStmt());
1858 return;
1859 }
1860
1861 // Handle case ranges.
1862 if (S.getRHS()) {
1863 EmitCaseStmtRange(S, Attrs);
1864 return;
1865 }
1866
1867 llvm::ConstantInt *CaseVal =
1868 Builder.getInt(S.getLHS()->EvaluateKnownConstInt(getContext()));
1869
1870 // Emit debuginfo for the case value if it is an enum value.
1871 const ConstantExpr *CE;
1872 if (auto ICE = dyn_cast<ImplicitCastExpr>(S.getLHS()))
1873 CE = dyn_cast<ConstantExpr>(ICE->getSubExpr());
1874 else
1875 CE = dyn_cast<ConstantExpr>(S.getLHS());
1876 if (CE) {
1877 if (auto DE = dyn_cast<DeclRefExpr>(CE->getSubExpr()))
1878 if (CGDebugInfo *Dbg = getDebugInfo())
1879 if (CGM.getCodeGenOpts().hasReducedDebugInfo())
1880 Dbg->EmitGlobalVariable(DE->getDecl(),
1881 APValue(llvm::APSInt(CaseVal->getValue())));
1882 }
1883
1884 if (SwitchLikelihood)
1885 SwitchLikelihood->push_back(Stmt::getLikelihood(Attrs));
1886
1887 // If the body of the case is just a 'break', try to not emit an empty block.
1888 // If we're profiling or we're not optimizing, leave the block in for better
1889 // debug and coverage analysis.
1890 if (!CGM.getCodeGenOpts().hasProfileClangInstr() &&
1891 CGM.getCodeGenOpts().OptimizationLevel > 0 &&
1892 isa<BreakStmt>(S.getSubStmt())) {
1893 JumpDest Block = BreakContinueStack.back().BreakBlock;
1894
1895 // Only do this optimization if there are no cleanups that need emitting.
1896 if (isObviouslyBranchWithoutCleanups(Block)) {
1897 if (SwitchWeights)
1898 SwitchWeights->push_back(getProfileCount(&S));
1899 SwitchInsn->addCase(CaseVal, Block.getBlock());
1900
1901 // If there was a fallthrough into this case, make sure to redirect it to
1902 // the end of the switch as well.
1903 if (Builder.GetInsertBlock()) {
1904 Builder.CreateBr(Block.getBlock());
1905 Builder.ClearInsertionPoint();
1906 }
1907 return;
1908 }
1909 }
1910
1911 llvm::BasicBlock *CaseDest = createBasicBlock("sw.bb");
1912 EmitBlockWithFallThrough(CaseDest, &S);
1913 if (SwitchWeights)
1914 SwitchWeights->push_back(getProfileCount(&S));
1915 SwitchInsn->addCase(CaseVal, CaseDest);
1916
1917 // Recursively emitting the statement is acceptable, but is not wonderful for
1918 // code where we have many case statements nested together, i.e.:
1919 // case 1:
1920 // case 2:
1921 // case 3: etc.
1922 // Handling this recursively will create a new block for each case statement
1923 // that falls through to the next case which is IR intensive. It also causes
1924 // deep recursion which can run into stack depth limitations. Handle
1925 // sequential non-range case statements specially.
1926 //
1927 // TODO When the next case has a likelihood attribute the code returns to the
1928 // recursive algorithm. Maybe improve this case if it becomes common practice
1929 // to use a lot of attributes.
1930 const CaseStmt *CurCase = &S;
1931 const CaseStmt *NextCase = dyn_cast<CaseStmt>(S.getSubStmt());
1932
1933 // Otherwise, iteratively add consecutive cases to this switch stmt.
1934 while (NextCase && NextCase->getRHS() == nullptr) {
1935 CurCase = NextCase;
1936 llvm::ConstantInt *CaseVal =
1937 Builder.getInt(CurCase->getLHS()->EvaluateKnownConstInt(getContext()));
1938
1939 if (SwitchWeights)
1940 SwitchWeights->push_back(getProfileCount(NextCase));
1941 if (CGM.getCodeGenOpts().hasProfileClangInstr()) {
1942 CaseDest = createBasicBlock("sw.bb");
1943 EmitBlockWithFallThrough(CaseDest, CurCase);
1944 }
1945 // Since this loop is only executed when the CaseStmt has no attributes
1946 // use a hard-coded value.
1947 if (SwitchLikelihood)
1948 SwitchLikelihood->push_back(Stmt::LH_None);
1949
1950 SwitchInsn->addCase(CaseVal, CaseDest);
1951 NextCase = dyn_cast<CaseStmt>(CurCase->getSubStmt());
1952 }
1953
1954 // Generate a stop point for debug info if the case statement is
1955 // followed by a default statement. A fallthrough case before a
1956 // default case gets its own branch target.
1957 if (CurCase->getSubStmt()->getStmtClass() == Stmt::DefaultStmtClass)
1958 EmitStopPoint(CurCase);
1959
1960 // Normal default recursion for non-cases.
1961 EmitStmt(CurCase->getSubStmt());
1962 }
1963
EmitDefaultStmt(const DefaultStmt & S,ArrayRef<const Attr * > Attrs)1964 void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S,
1965 ArrayRef<const Attr *> Attrs) {
1966 // If there is no enclosing switch instance that we're aware of, then this
1967 // default statement can be elided. This situation only happens when we've
1968 // constant-folded the switch.
1969 if (!SwitchInsn) {
1970 EmitStmt(S.getSubStmt());
1971 return;
1972 }
1973
1974 llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest();
1975 assert(DefaultBlock->empty() &&
1976 "EmitDefaultStmt: Default block already defined?");
1977
1978 if (SwitchLikelihood)
1979 SwitchLikelihood->front() = Stmt::getLikelihood(Attrs);
1980
1981 EmitBlockWithFallThrough(DefaultBlock, &S);
1982
1983 EmitStmt(S.getSubStmt());
1984 }
1985
1986 /// CollectStatementsForCase - Given the body of a 'switch' statement and a
1987 /// constant value that is being switched on, see if we can dead code eliminate
1988 /// the body of the switch to a simple series of statements to emit. Basically,
1989 /// on a switch (5) we want to find these statements:
1990 /// case 5:
1991 /// printf(...); <--
1992 /// ++i; <--
1993 /// break;
1994 ///
1995 /// and add them to the ResultStmts vector. If it is unsafe to do this
1996 /// transformation (for example, one of the elided statements contains a label
1997 /// that might be jumped to), return CSFC_Failure. If we handled it and 'S'
1998 /// should include statements after it (e.g. the printf() line is a substmt of
1999 /// the case) then return CSFC_FallThrough. If we handled it and found a break
2000 /// statement, then return CSFC_Success.
2001 ///
2002 /// If Case is non-null, then we are looking for the specified case, checking
2003 /// that nothing we jump over contains labels. If Case is null, then we found
2004 /// the case and are looking for the break.
2005 ///
2006 /// If the recursive walk actually finds our Case, then we set FoundCase to
2007 /// true.
2008 ///
2009 enum CSFC_Result { CSFC_Failure, CSFC_FallThrough, CSFC_Success };
CollectStatementsForCase(const Stmt * S,const SwitchCase * Case,bool & FoundCase,SmallVectorImpl<const Stmt * > & ResultStmts)2010 static CSFC_Result CollectStatementsForCase(const Stmt *S,
2011 const SwitchCase *Case,
2012 bool &FoundCase,
2013 SmallVectorImpl<const Stmt*> &ResultStmts) {
2014 // If this is a null statement, just succeed.
2015 if (!S)
2016 return Case ? CSFC_Success : CSFC_FallThrough;
2017
2018 // If this is the switchcase (case 4: or default) that we're looking for, then
2019 // we're in business. Just add the substatement.
2020 if (const SwitchCase *SC = dyn_cast<SwitchCase>(S)) {
2021 if (S == Case) {
2022 FoundCase = true;
2023 return CollectStatementsForCase(SC->getSubStmt(), nullptr, FoundCase,
2024 ResultStmts);
2025 }
2026
2027 // Otherwise, this is some other case or default statement, just ignore it.
2028 return CollectStatementsForCase(SC->getSubStmt(), Case, FoundCase,
2029 ResultStmts);
2030 }
2031
2032 // If we are in the live part of the code and we found our break statement,
2033 // return a success!
2034 if (!Case && isa<BreakStmt>(S))
2035 return CSFC_Success;
2036
2037 // If this is a switch statement, then it might contain the SwitchCase, the
2038 // break, or neither.
2039 if (const CompoundStmt *CS = dyn_cast<CompoundStmt>(S)) {
2040 // Handle this as two cases: we might be looking for the SwitchCase (if so
2041 // the skipped statements must be skippable) or we might already have it.
2042 CompoundStmt::const_body_iterator I = CS->body_begin(), E = CS->body_end();
2043 bool StartedInLiveCode = FoundCase;
2044 unsigned StartSize = ResultStmts.size();
2045
2046 // If we've not found the case yet, scan through looking for it.
2047 if (Case) {
2048 // Keep track of whether we see a skipped declaration. The code could be
2049 // using the declaration even if it is skipped, so we can't optimize out
2050 // the decl if the kept statements might refer to it.
2051 bool HadSkippedDecl = false;
2052
2053 // If we're looking for the case, just see if we can skip each of the
2054 // substatements.
2055 for (; Case && I != E; ++I) {
2056 HadSkippedDecl |= CodeGenFunction::mightAddDeclToScope(*I);
2057
2058 switch (CollectStatementsForCase(*I, Case, FoundCase, ResultStmts)) {
2059 case CSFC_Failure: return CSFC_Failure;
2060 case CSFC_Success:
2061 // A successful result means that either 1) that the statement doesn't
2062 // have the case and is skippable, or 2) does contain the case value
2063 // and also contains the break to exit the switch. In the later case,
2064 // we just verify the rest of the statements are elidable.
2065 if (FoundCase) {
2066 // If we found the case and skipped declarations, we can't do the
2067 // optimization.
2068 if (HadSkippedDecl)
2069 return CSFC_Failure;
2070
2071 for (++I; I != E; ++I)
2072 if (CodeGenFunction::ContainsLabel(*I, true))
2073 return CSFC_Failure;
2074 return CSFC_Success;
2075 }
2076 break;
2077 case CSFC_FallThrough:
2078 // If we have a fallthrough condition, then we must have found the
2079 // case started to include statements. Consider the rest of the
2080 // statements in the compound statement as candidates for inclusion.
2081 assert(FoundCase && "Didn't find case but returned fallthrough?");
2082 // We recursively found Case, so we're not looking for it anymore.
2083 Case = nullptr;
2084
2085 // If we found the case and skipped declarations, we can't do the
2086 // optimization.
2087 if (HadSkippedDecl)
2088 return CSFC_Failure;
2089 break;
2090 }
2091 }
2092
2093 if (!FoundCase)
2094 return CSFC_Success;
2095
2096 assert(!HadSkippedDecl && "fallthrough after skipping decl");
2097 }
2098
2099 // If we have statements in our range, then we know that the statements are
2100 // live and need to be added to the set of statements we're tracking.
2101 bool AnyDecls = false;
2102 for (; I != E; ++I) {
2103 AnyDecls |= CodeGenFunction::mightAddDeclToScope(*I);
2104
2105 switch (CollectStatementsForCase(*I, nullptr, FoundCase, ResultStmts)) {
2106 case CSFC_Failure: return CSFC_Failure;
2107 case CSFC_FallThrough:
2108 // A fallthrough result means that the statement was simple and just
2109 // included in ResultStmt, keep adding them afterwards.
2110 break;
2111 case CSFC_Success:
2112 // A successful result means that we found the break statement and
2113 // stopped statement inclusion. We just ensure that any leftover stmts
2114 // are skippable and return success ourselves.
2115 for (++I; I != E; ++I)
2116 if (CodeGenFunction::ContainsLabel(*I, true))
2117 return CSFC_Failure;
2118 return CSFC_Success;
2119 }
2120 }
2121
2122 // If we're about to fall out of a scope without hitting a 'break;', we
2123 // can't perform the optimization if there were any decls in that scope
2124 // (we'd lose their end-of-lifetime).
2125 if (AnyDecls) {
2126 // If the entire compound statement was live, there's one more thing we
2127 // can try before giving up: emit the whole thing as a single statement.
2128 // We can do that unless the statement contains a 'break;'.
2129 // FIXME: Such a break must be at the end of a construct within this one.
2130 // We could emit this by just ignoring the BreakStmts entirely.
2131 if (StartedInLiveCode && !CodeGenFunction::containsBreak(S)) {
2132 ResultStmts.resize(StartSize);
2133 ResultStmts.push_back(S);
2134 } else {
2135 return CSFC_Failure;
2136 }
2137 }
2138
2139 return CSFC_FallThrough;
2140 }
2141
2142 // Okay, this is some other statement that we don't handle explicitly, like a
2143 // for statement or increment etc. If we are skipping over this statement,
2144 // just verify it doesn't have labels, which would make it invalid to elide.
2145 if (Case) {
2146 if (CodeGenFunction::ContainsLabel(S, true))
2147 return CSFC_Failure;
2148 return CSFC_Success;
2149 }
2150
2151 // Otherwise, we want to include this statement. Everything is cool with that
2152 // so long as it doesn't contain a break out of the switch we're in.
2153 if (CodeGenFunction::containsBreak(S)) return CSFC_Failure;
2154
2155 // Otherwise, everything is great. Include the statement and tell the caller
2156 // that we fall through and include the next statement as well.
2157 ResultStmts.push_back(S);
2158 return CSFC_FallThrough;
2159 }
2160
2161 /// FindCaseStatementsForValue - Find the case statement being jumped to and
2162 /// then invoke CollectStatementsForCase to find the list of statements to emit
2163 /// for a switch on constant. See the comment above CollectStatementsForCase
2164 /// for more details.
FindCaseStatementsForValue(const SwitchStmt & S,const llvm::APSInt & ConstantCondValue,SmallVectorImpl<const Stmt * > & ResultStmts,ASTContext & C,const SwitchCase * & ResultCase)2165 static bool FindCaseStatementsForValue(const SwitchStmt &S,
2166 const llvm::APSInt &ConstantCondValue,
2167 SmallVectorImpl<const Stmt*> &ResultStmts,
2168 ASTContext &C,
2169 const SwitchCase *&ResultCase) {
2170 // First step, find the switch case that is being branched to. We can do this
2171 // efficiently by scanning the SwitchCase list.
2172 const SwitchCase *Case = S.getSwitchCaseList();
2173 const DefaultStmt *DefaultCase = nullptr;
2174
2175 for (; Case; Case = Case->getNextSwitchCase()) {
2176 // It's either a default or case. Just remember the default statement in
2177 // case we're not jumping to any numbered cases.
2178 if (const DefaultStmt *DS = dyn_cast<DefaultStmt>(Case)) {
2179 DefaultCase = DS;
2180 continue;
2181 }
2182
2183 // Check to see if this case is the one we're looking for.
2184 const CaseStmt *CS = cast<CaseStmt>(Case);
2185 // Don't handle case ranges yet.
2186 if (CS->getRHS()) return false;
2187
2188 // If we found our case, remember it as 'case'.
2189 if (CS->getLHS()->EvaluateKnownConstInt(C) == ConstantCondValue)
2190 break;
2191 }
2192
2193 // If we didn't find a matching case, we use a default if it exists, or we
2194 // elide the whole switch body!
2195 if (!Case) {
2196 // It is safe to elide the body of the switch if it doesn't contain labels
2197 // etc. If it is safe, return successfully with an empty ResultStmts list.
2198 if (!DefaultCase)
2199 return !CodeGenFunction::ContainsLabel(&S);
2200 Case = DefaultCase;
2201 }
2202
2203 // Ok, we know which case is being jumped to, try to collect all the
2204 // statements that follow it. This can fail for a variety of reasons. Also,
2205 // check to see that the recursive walk actually found our case statement.
2206 // Insane cases like this can fail to find it in the recursive walk since we
2207 // don't handle every stmt kind:
2208 // switch (4) {
2209 // while (1) {
2210 // case 4: ...
2211 bool FoundCase = false;
2212 ResultCase = Case;
2213 return CollectStatementsForCase(S.getBody(), Case, FoundCase,
2214 ResultStmts) != CSFC_Failure &&
2215 FoundCase;
2216 }
2217
2218 static std::optional<SmallVector<uint64_t, 16>>
getLikelihoodWeights(ArrayRef<Stmt::Likelihood> Likelihoods)2219 getLikelihoodWeights(ArrayRef<Stmt::Likelihood> Likelihoods) {
2220 // Are there enough branches to weight them?
2221 if (Likelihoods.size() <= 1)
2222 return std::nullopt;
2223
2224 uint64_t NumUnlikely = 0;
2225 uint64_t NumNone = 0;
2226 uint64_t NumLikely = 0;
2227 for (const auto LH : Likelihoods) {
2228 switch (LH) {
2229 case Stmt::LH_Unlikely:
2230 ++NumUnlikely;
2231 break;
2232 case Stmt::LH_None:
2233 ++NumNone;
2234 break;
2235 case Stmt::LH_Likely:
2236 ++NumLikely;
2237 break;
2238 }
2239 }
2240
2241 // Is there a likelihood attribute used?
2242 if (NumUnlikely == 0 && NumLikely == 0)
2243 return std::nullopt;
2244
2245 // When multiple cases share the same code they can be combined during
2246 // optimization. In that case the weights of the branch will be the sum of
2247 // the individual weights. Make sure the combined sum of all neutral cases
2248 // doesn't exceed the value of a single likely attribute.
2249 // The additions both avoid divisions by 0 and make sure the weights of None
2250 // don't exceed the weight of Likely.
2251 const uint64_t Likely = INT32_MAX / (NumLikely + 2);
2252 const uint64_t None = Likely / (NumNone + 1);
2253 const uint64_t Unlikely = 0;
2254
2255 SmallVector<uint64_t, 16> Result;
2256 Result.reserve(Likelihoods.size());
2257 for (const auto LH : Likelihoods) {
2258 switch (LH) {
2259 case Stmt::LH_Unlikely:
2260 Result.push_back(Unlikely);
2261 break;
2262 case Stmt::LH_None:
2263 Result.push_back(None);
2264 break;
2265 case Stmt::LH_Likely:
2266 Result.push_back(Likely);
2267 break;
2268 }
2269 }
2270
2271 return Result;
2272 }
2273
EmitSwitchStmt(const SwitchStmt & S)2274 void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) {
2275 // Handle nested switch statements.
2276 llvm::SwitchInst *SavedSwitchInsn = SwitchInsn;
2277 SmallVector<uint64_t, 16> *SavedSwitchWeights = SwitchWeights;
2278 SmallVector<Stmt::Likelihood, 16> *SavedSwitchLikelihood = SwitchLikelihood;
2279 llvm::BasicBlock *SavedCRBlock = CaseRangeBlock;
2280
2281 // See if we can constant fold the condition of the switch and therefore only
2282 // emit the live case statement (if any) of the switch.
2283 llvm::APSInt ConstantCondValue;
2284 if (ConstantFoldsToSimpleInteger(S.getCond(), ConstantCondValue)) {
2285 SmallVector<const Stmt*, 4> CaseStmts;
2286 const SwitchCase *Case = nullptr;
2287 if (FindCaseStatementsForValue(S, ConstantCondValue, CaseStmts,
2288 getContext(), Case)) {
2289 if (Case)
2290 incrementProfileCounter(Case);
2291 RunCleanupsScope ExecutedScope(*this);
2292
2293 if (S.getInit())
2294 EmitStmt(S.getInit());
2295
2296 // Emit the condition variable if needed inside the entire cleanup scope
2297 // used by this special case for constant folded switches.
2298 if (S.getConditionVariable())
2299 EmitDecl(*S.getConditionVariable(), /*EvaluateConditionDecl=*/true);
2300
2301 // At this point, we are no longer "within" a switch instance, so
2302 // we can temporarily enforce this to ensure that any embedded case
2303 // statements are not emitted.
2304 SwitchInsn = nullptr;
2305
2306 // Okay, we can dead code eliminate everything except this case. Emit the
2307 // specified series of statements and we're good.
2308 for (const Stmt *CaseStmt : CaseStmts)
2309 EmitStmt(CaseStmt);
2310 incrementProfileCounter(&S);
2311 PGO->markStmtMaybeUsed(S.getBody());
2312
2313 // Now we want to restore the saved switch instance so that nested
2314 // switches continue to function properly
2315 SwitchInsn = SavedSwitchInsn;
2316
2317 return;
2318 }
2319 }
2320
2321 JumpDest SwitchExit = getJumpDestInCurrentScope("sw.epilog");
2322
2323 RunCleanupsScope ConditionScope(*this);
2324
2325 if (S.getInit())
2326 EmitStmt(S.getInit());
2327
2328 if (S.getConditionVariable())
2329 EmitDecl(*S.getConditionVariable());
2330 llvm::Value *CondV = EmitScalarExpr(S.getCond());
2331 MaybeEmitDeferredVarDeclInit(S.getConditionVariable());
2332
2333 // Create basic block to hold stuff that comes after switch
2334 // statement. We also need to create a default block now so that
2335 // explicit case ranges tests can have a place to jump to on
2336 // failure.
2337 llvm::BasicBlock *DefaultBlock = createBasicBlock("sw.default");
2338 SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock);
2339 addInstToNewSourceAtom(SwitchInsn, CondV);
2340
2341 if (HLSLControlFlowAttr != HLSLControlFlowHintAttr::SpellingNotCalculated) {
2342 llvm::MDBuilder MDHelper(CGM.getLLVMContext());
2343 llvm::ConstantInt *BranchHintConstant =
2344 HLSLControlFlowAttr ==
2345 HLSLControlFlowHintAttr::Spelling::Microsoft_branch
2346 ? llvm::ConstantInt::get(CGM.Int32Ty, 1)
2347 : llvm::ConstantInt::get(CGM.Int32Ty, 2);
2348 llvm::Metadata *Vals[] = {MDHelper.createString("hlsl.controlflow.hint"),
2349 MDHelper.createConstant(BranchHintConstant)};
2350 SwitchInsn->setMetadata("hlsl.controlflow.hint",
2351 llvm::MDNode::get(CGM.getLLVMContext(), Vals));
2352 }
2353
2354 if (PGO->haveRegionCounts()) {
2355 // Walk the SwitchCase list to find how many there are.
2356 uint64_t DefaultCount = 0;
2357 unsigned NumCases = 0;
2358 for (const SwitchCase *Case = S.getSwitchCaseList();
2359 Case;
2360 Case = Case->getNextSwitchCase()) {
2361 if (isa<DefaultStmt>(Case))
2362 DefaultCount = getProfileCount(Case);
2363 NumCases += 1;
2364 }
2365 SwitchWeights = new SmallVector<uint64_t, 16>();
2366 SwitchWeights->reserve(NumCases);
2367 // The default needs to be first. We store the edge count, so we already
2368 // know the right weight.
2369 SwitchWeights->push_back(DefaultCount);
2370 } else if (CGM.getCodeGenOpts().OptimizationLevel) {
2371 SwitchLikelihood = new SmallVector<Stmt::Likelihood, 16>();
2372 // Initialize the default case.
2373 SwitchLikelihood->push_back(Stmt::LH_None);
2374 }
2375
2376 CaseRangeBlock = DefaultBlock;
2377
2378 // Clear the insertion point to indicate we are in unreachable code.
2379 Builder.ClearInsertionPoint();
2380
2381 // All break statements jump to NextBlock. If BreakContinueStack is non-empty
2382 // then reuse last ContinueBlock.
2383 JumpDest OuterContinue;
2384 if (!BreakContinueStack.empty())
2385 OuterContinue = BreakContinueStack.back().ContinueBlock;
2386
2387 BreakContinueStack.push_back(BreakContinue(SwitchExit, OuterContinue));
2388
2389 // Emit switch body.
2390 EmitStmt(S.getBody());
2391
2392 BreakContinueStack.pop_back();
2393
2394 // Update the default block in case explicit case range tests have
2395 // been chained on top.
2396 SwitchInsn->setDefaultDest(CaseRangeBlock);
2397
2398 // If a default was never emitted:
2399 if (!DefaultBlock->getParent()) {
2400 // If we have cleanups, emit the default block so that there's a
2401 // place to jump through the cleanups from.
2402 if (ConditionScope.requiresCleanups()) {
2403 EmitBlock(DefaultBlock);
2404
2405 // Otherwise, just forward the default block to the switch end.
2406 } else {
2407 DefaultBlock->replaceAllUsesWith(SwitchExit.getBlock());
2408 delete DefaultBlock;
2409 }
2410 }
2411
2412 ConditionScope.ForceCleanup();
2413
2414 // Emit continuation.
2415 EmitBlock(SwitchExit.getBlock(), true);
2416 incrementProfileCounter(&S);
2417
2418 // If the switch has a condition wrapped by __builtin_unpredictable,
2419 // create metadata that specifies that the switch is unpredictable.
2420 // Don't bother if not optimizing because that metadata would not be used.
2421 auto *Call = dyn_cast<CallExpr>(S.getCond());
2422 if (Call && CGM.getCodeGenOpts().OptimizationLevel != 0) {
2423 auto *FD = dyn_cast_or_null<FunctionDecl>(Call->getCalleeDecl());
2424 if (FD && FD->getBuiltinID() == Builtin::BI__builtin_unpredictable) {
2425 llvm::MDBuilder MDHelper(getLLVMContext());
2426 SwitchInsn->setMetadata(llvm::LLVMContext::MD_unpredictable,
2427 MDHelper.createUnpredictable());
2428 }
2429 }
2430
2431 if (SwitchWeights) {
2432 assert(SwitchWeights->size() == 1 + SwitchInsn->getNumCases() &&
2433 "switch weights do not match switch cases");
2434 // If there's only one jump destination there's no sense weighting it.
2435 if (SwitchWeights->size() > 1)
2436 SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof,
2437 createProfileWeights(*SwitchWeights));
2438 delete SwitchWeights;
2439 } else if (SwitchLikelihood) {
2440 assert(SwitchLikelihood->size() == 1 + SwitchInsn->getNumCases() &&
2441 "switch likelihoods do not match switch cases");
2442 std::optional<SmallVector<uint64_t, 16>> LHW =
2443 getLikelihoodWeights(*SwitchLikelihood);
2444 if (LHW) {
2445 llvm::MDBuilder MDHelper(CGM.getLLVMContext());
2446 SwitchInsn->setMetadata(llvm::LLVMContext::MD_prof,
2447 createProfileWeights(*LHW));
2448 }
2449 delete SwitchLikelihood;
2450 }
2451 SwitchInsn = SavedSwitchInsn;
2452 SwitchWeights = SavedSwitchWeights;
2453 SwitchLikelihood = SavedSwitchLikelihood;
2454 CaseRangeBlock = SavedCRBlock;
2455 }
2456
2457 static std::string
SimplifyConstraint(const char * Constraint,const TargetInfo & Target,SmallVectorImpl<TargetInfo::ConstraintInfo> * OutCons=nullptr)2458 SimplifyConstraint(const char *Constraint, const TargetInfo &Target,
2459 SmallVectorImpl<TargetInfo::ConstraintInfo> *OutCons=nullptr) {
2460 std::string Result;
2461
2462 while (*Constraint) {
2463 switch (*Constraint) {
2464 default:
2465 Result += Target.convertConstraint(Constraint);
2466 break;
2467 // Ignore these
2468 case '*':
2469 case '?':
2470 case '!':
2471 case '=': // Will see this and the following in mult-alt constraints.
2472 case '+':
2473 break;
2474 case '#': // Ignore the rest of the constraint alternative.
2475 while (Constraint[1] && Constraint[1] != ',')
2476 Constraint++;
2477 break;
2478 case '&':
2479 case '%':
2480 Result += *Constraint;
2481 while (Constraint[1] && Constraint[1] == *Constraint)
2482 Constraint++;
2483 break;
2484 case ',':
2485 Result += "|";
2486 break;
2487 case 'g':
2488 Result += "imr";
2489 break;
2490 case '[': {
2491 assert(OutCons &&
2492 "Must pass output names to constraints with a symbolic name");
2493 unsigned Index;
2494 bool result = Target.resolveSymbolicName(Constraint, *OutCons, Index);
2495 assert(result && "Could not resolve symbolic name"); (void)result;
2496 Result += llvm::utostr(Index);
2497 break;
2498 }
2499 }
2500
2501 Constraint++;
2502 }
2503
2504 return Result;
2505 }
2506
2507 /// AddVariableConstraints - Look at AsmExpr and if it is a variable declared
2508 /// as using a particular register add that as a constraint that will be used
2509 /// in this asm stmt.
2510 static std::string
AddVariableConstraints(const std::string & Constraint,const Expr & AsmExpr,const TargetInfo & Target,CodeGenModule & CGM,const AsmStmt & Stmt,const bool EarlyClobber,std::string * GCCReg=nullptr)2511 AddVariableConstraints(const std::string &Constraint, const Expr &AsmExpr,
2512 const TargetInfo &Target, CodeGenModule &CGM,
2513 const AsmStmt &Stmt, const bool EarlyClobber,
2514 std::string *GCCReg = nullptr) {
2515 const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(&AsmExpr);
2516 if (!AsmDeclRef)
2517 return Constraint;
2518 const ValueDecl &Value = *AsmDeclRef->getDecl();
2519 const VarDecl *Variable = dyn_cast<VarDecl>(&Value);
2520 if (!Variable)
2521 return Constraint;
2522 if (Variable->getStorageClass() != SC_Register)
2523 return Constraint;
2524 AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>();
2525 if (!Attr)
2526 return Constraint;
2527 StringRef Register = Attr->getLabel();
2528 assert(Target.isValidGCCRegisterName(Register));
2529 // We're using validateOutputConstraint here because we only care if
2530 // this is a register constraint.
2531 TargetInfo::ConstraintInfo Info(Constraint, "");
2532 if (Target.validateOutputConstraint(Info) &&
2533 !Info.allowsRegister()) {
2534 CGM.ErrorUnsupported(&Stmt, "__asm__");
2535 return Constraint;
2536 }
2537 // Canonicalize the register here before returning it.
2538 Register = Target.getNormalizedGCCRegisterName(Register);
2539 if (GCCReg != nullptr)
2540 *GCCReg = Register.str();
2541 return (EarlyClobber ? "&{" : "{") + Register.str() + "}";
2542 }
2543
EmitAsmInputLValue(const TargetInfo::ConstraintInfo & Info,LValue InputValue,QualType InputType,std::string & ConstraintStr,SourceLocation Loc)2544 std::pair<llvm::Value*, llvm::Type *> CodeGenFunction::EmitAsmInputLValue(
2545 const TargetInfo::ConstraintInfo &Info, LValue InputValue,
2546 QualType InputType, std::string &ConstraintStr, SourceLocation Loc) {
2547 if (Info.allowsRegister() || !Info.allowsMemory()) {
2548 if (CodeGenFunction::hasScalarEvaluationKind(InputType))
2549 return {EmitLoadOfLValue(InputValue, Loc).getScalarVal(), nullptr};
2550
2551 llvm::Type *Ty = ConvertType(InputType);
2552 uint64_t Size = CGM.getDataLayout().getTypeSizeInBits(Ty);
2553 if ((Size <= 64 && llvm::isPowerOf2_64(Size)) ||
2554 getTargetHooks().isScalarizableAsmOperand(*this, Ty)) {
2555 Ty = llvm::IntegerType::get(getLLVMContext(), Size);
2556
2557 return {Builder.CreateLoad(InputValue.getAddress().withElementType(Ty)),
2558 nullptr};
2559 }
2560 }
2561
2562 Address Addr = InputValue.getAddress();
2563 ConstraintStr += '*';
2564 return {InputValue.getPointer(*this), Addr.getElementType()};
2565 }
2566
2567 std::pair<llvm::Value *, llvm::Type *>
EmitAsmInput(const TargetInfo::ConstraintInfo & Info,const Expr * InputExpr,std::string & ConstraintStr)2568 CodeGenFunction::EmitAsmInput(const TargetInfo::ConstraintInfo &Info,
2569 const Expr *InputExpr,
2570 std::string &ConstraintStr) {
2571 // If this can't be a register or memory, i.e., has to be a constant
2572 // (immediate or symbolic), try to emit it as such.
2573 if (!Info.allowsRegister() && !Info.allowsMemory()) {
2574 if (Info.requiresImmediateConstant()) {
2575 Expr::EvalResult EVResult;
2576 InputExpr->EvaluateAsRValue(EVResult, getContext(), true);
2577
2578 llvm::APSInt IntResult;
2579 if (EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(),
2580 getContext()))
2581 return {llvm::ConstantInt::get(getLLVMContext(), IntResult), nullptr};
2582 }
2583
2584 Expr::EvalResult Result;
2585 if (InputExpr->EvaluateAsInt(Result, getContext()))
2586 return {llvm::ConstantInt::get(getLLVMContext(), Result.Val.getInt()),
2587 nullptr};
2588 }
2589
2590 if (Info.allowsRegister() || !Info.allowsMemory())
2591 if (CodeGenFunction::hasScalarEvaluationKind(InputExpr->getType()))
2592 return {EmitScalarExpr(InputExpr), nullptr};
2593 if (InputExpr->getStmtClass() == Expr::CXXThisExprClass)
2594 return {EmitScalarExpr(InputExpr), nullptr};
2595 InputExpr = InputExpr->IgnoreParenNoopCasts(getContext());
2596 LValue Dest = EmitLValue(InputExpr);
2597 return EmitAsmInputLValue(Info, Dest, InputExpr->getType(), ConstraintStr,
2598 InputExpr->getExprLoc());
2599 }
2600
2601 /// getAsmSrcLocInfo - Return the !srcloc metadata node to attach to an inline
2602 /// asm call instruction. The !srcloc MDNode contains a list of constant
2603 /// integers which are the source locations of the start of each line in the
2604 /// asm.
getAsmSrcLocInfo(const StringLiteral * Str,CodeGenFunction & CGF)2605 static llvm::MDNode *getAsmSrcLocInfo(const StringLiteral *Str,
2606 CodeGenFunction &CGF) {
2607 SmallVector<llvm::Metadata *, 8> Locs;
2608 // Add the location of the first line to the MDNode.
2609 Locs.push_back(llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2610 CGF.Int64Ty, Str->getBeginLoc().getRawEncoding())));
2611 StringRef StrVal = Str->getString();
2612 if (!StrVal.empty()) {
2613 const SourceManager &SM = CGF.CGM.getContext().getSourceManager();
2614 const LangOptions &LangOpts = CGF.CGM.getLangOpts();
2615 unsigned StartToken = 0;
2616 unsigned ByteOffset = 0;
2617
2618 // Add the location of the start of each subsequent line of the asm to the
2619 // MDNode.
2620 for (unsigned i = 0, e = StrVal.size() - 1; i != e; ++i) {
2621 if (StrVal[i] != '\n') continue;
2622 SourceLocation LineLoc = Str->getLocationOfByte(
2623 i + 1, SM, LangOpts, CGF.getTarget(), &StartToken, &ByteOffset);
2624 Locs.push_back(llvm::ConstantAsMetadata::get(
2625 llvm::ConstantInt::get(CGF.Int64Ty, LineLoc.getRawEncoding())));
2626 }
2627 }
2628
2629 return llvm::MDNode::get(CGF.getLLVMContext(), Locs);
2630 }
2631
UpdateAsmCallInst(llvm::CallBase & Result,bool HasSideEffect,bool HasUnwindClobber,bool ReadOnly,bool ReadNone,bool NoMerge,bool NoConvergent,const AsmStmt & S,const std::vector<llvm::Type * > & ResultRegTypes,const std::vector<llvm::Type * > & ArgElemTypes,CodeGenFunction & CGF,std::vector<llvm::Value * > & RegResults)2632 static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect,
2633 bool HasUnwindClobber, bool ReadOnly,
2634 bool ReadNone, bool NoMerge, bool NoConvergent,
2635 const AsmStmt &S,
2636 const std::vector<llvm::Type *> &ResultRegTypes,
2637 const std::vector<llvm::Type *> &ArgElemTypes,
2638 CodeGenFunction &CGF,
2639 std::vector<llvm::Value *> &RegResults) {
2640 if (!HasUnwindClobber)
2641 Result.addFnAttr(llvm::Attribute::NoUnwind);
2642
2643 if (NoMerge)
2644 Result.addFnAttr(llvm::Attribute::NoMerge);
2645 // Attach readnone and readonly attributes.
2646 if (!HasSideEffect) {
2647 if (ReadNone)
2648 Result.setDoesNotAccessMemory();
2649 else if (ReadOnly)
2650 Result.setOnlyReadsMemory();
2651 }
2652
2653 // Add elementtype attribute for indirect constraints.
2654 for (auto Pair : llvm::enumerate(ArgElemTypes)) {
2655 if (Pair.value()) {
2656 auto Attr = llvm::Attribute::get(
2657 CGF.getLLVMContext(), llvm::Attribute::ElementType, Pair.value());
2658 Result.addParamAttr(Pair.index(), Attr);
2659 }
2660 }
2661
2662 // Slap the source location of the inline asm into a !srcloc metadata on the
2663 // call.
2664 const StringLiteral *SL;
2665 if (const auto *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S);
2666 gccAsmStmt &&
2667 (SL = dyn_cast<StringLiteral>(gccAsmStmt->getAsmStringExpr()))) {
2668 Result.setMetadata("srcloc", getAsmSrcLocInfo(SL, CGF));
2669 } else {
2670 // At least put the line number on MS inline asm blobs and GCC asm constexpr
2671 // strings.
2672 llvm::Constant *Loc =
2673 llvm::ConstantInt::get(CGF.Int64Ty, S.getAsmLoc().getRawEncoding());
2674 Result.setMetadata("srcloc",
2675 llvm::MDNode::get(CGF.getLLVMContext(),
2676 llvm::ConstantAsMetadata::get(Loc)));
2677 }
2678
2679 // Make inline-asm calls Key for the debug info feature Key Instructions.
2680 CGF.addInstToNewSourceAtom(&Result, nullptr);
2681
2682 if (!NoConvergent && CGF.getLangOpts().assumeFunctionsAreConvergent())
2683 // Conservatively, mark all inline asm blocks in CUDA or OpenCL as
2684 // convergent (meaning, they may call an intrinsically convergent op, such
2685 // as bar.sync, and so can't have certain optimizations applied around
2686 // them) unless it's explicitly marked 'noconvergent'.
2687 Result.addFnAttr(llvm::Attribute::Convergent);
2688 // Extract all of the register value results from the asm.
2689 if (ResultRegTypes.size() == 1) {
2690 RegResults.push_back(&Result);
2691 } else {
2692 for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) {
2693 llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult");
2694 RegResults.push_back(Tmp);
2695 }
2696 }
2697 }
2698
2699 static void
EmitAsmStores(CodeGenFunction & CGF,const AsmStmt & S,const llvm::ArrayRef<llvm::Value * > RegResults,const llvm::ArrayRef<llvm::Type * > ResultRegTypes,const llvm::ArrayRef<llvm::Type * > ResultTruncRegTypes,const llvm::ArrayRef<LValue> ResultRegDests,const llvm::ArrayRef<QualType> ResultRegQualTys,const llvm::BitVector & ResultTypeRequiresCast,const llvm::BitVector & ResultRegIsFlagReg)2700 EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S,
2701 const llvm::ArrayRef<llvm::Value *> RegResults,
2702 const llvm::ArrayRef<llvm::Type *> ResultRegTypes,
2703 const llvm::ArrayRef<llvm::Type *> ResultTruncRegTypes,
2704 const llvm::ArrayRef<LValue> ResultRegDests,
2705 const llvm::ArrayRef<QualType> ResultRegQualTys,
2706 const llvm::BitVector &ResultTypeRequiresCast,
2707 const llvm::BitVector &ResultRegIsFlagReg) {
2708 CGBuilderTy &Builder = CGF.Builder;
2709 CodeGenModule &CGM = CGF.CGM;
2710 llvm::LLVMContext &CTX = CGF.getLLVMContext();
2711
2712 assert(RegResults.size() == ResultRegTypes.size());
2713 assert(RegResults.size() == ResultTruncRegTypes.size());
2714 assert(RegResults.size() == ResultRegDests.size());
2715 // ResultRegDests can be also populated by addReturnRegisterOutputs() above,
2716 // in which case its size may grow.
2717 assert(ResultTypeRequiresCast.size() <= ResultRegDests.size());
2718 assert(ResultRegIsFlagReg.size() <= ResultRegDests.size());
2719
2720 for (unsigned i = 0, e = RegResults.size(); i != e; ++i) {
2721 llvm::Value *Tmp = RegResults[i];
2722 llvm::Type *TruncTy = ResultTruncRegTypes[i];
2723
2724 if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) {
2725 // Target must guarantee the Value `Tmp` here is lowered to a boolean
2726 // value.
2727 llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2);
2728 llvm::Value *IsBooleanValue =
2729 Builder.CreateCmp(llvm::CmpInst::ICMP_ULT, Tmp, Two);
2730 llvm::Function *FnAssume = CGM.getIntrinsic(llvm::Intrinsic::assume);
2731 Builder.CreateCall(FnAssume, IsBooleanValue);
2732 }
2733
2734 // If the result type of the LLVM IR asm doesn't match the result type of
2735 // the expression, do the conversion.
2736 if (ResultRegTypes[i] != TruncTy) {
2737
2738 // Truncate the integer result to the right size, note that TruncTy can be
2739 // a pointer.
2740 if (TruncTy->isFloatingPointTy())
2741 Tmp = Builder.CreateFPTrunc(Tmp, TruncTy);
2742 else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) {
2743 uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy);
2744 Tmp = Builder.CreateTrunc(
2745 Tmp, llvm::IntegerType::get(CTX, (unsigned)ResSize));
2746 Tmp = Builder.CreateIntToPtr(Tmp, TruncTy);
2747 } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) {
2748 uint64_t TmpSize =
2749 CGM.getDataLayout().getTypeSizeInBits(Tmp->getType());
2750 Tmp = Builder.CreatePtrToInt(
2751 Tmp, llvm::IntegerType::get(CTX, (unsigned)TmpSize));
2752 Tmp = Builder.CreateTrunc(Tmp, TruncTy);
2753 } else if (Tmp->getType()->isIntegerTy() && TruncTy->isIntegerTy()) {
2754 Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy);
2755 } else if (Tmp->getType()->isVectorTy() || TruncTy->isVectorTy()) {
2756 Tmp = Builder.CreateBitCast(Tmp, TruncTy);
2757 }
2758 }
2759
2760 ApplyAtomGroup Grp(CGF.getDebugInfo());
2761 LValue Dest = ResultRegDests[i];
2762 // ResultTypeRequiresCast elements correspond to the first
2763 // ResultTypeRequiresCast.size() elements of RegResults.
2764 if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) {
2765 unsigned Size = CGF.getContext().getTypeSize(ResultRegQualTys[i]);
2766 Address A = Dest.getAddress().withElementType(ResultRegTypes[i]);
2767 if (CGF.getTargetHooks().isScalarizableAsmOperand(CGF, TruncTy)) {
2768 llvm::StoreInst *S = Builder.CreateStore(Tmp, A);
2769 CGF.addInstToCurrentSourceAtom(S, S->getValueOperand());
2770 continue;
2771 }
2772
2773 QualType Ty =
2774 CGF.getContext().getIntTypeForBitwidth(Size, /*Signed=*/false);
2775 if (Ty.isNull()) {
2776 const Expr *OutExpr = S.getOutputExpr(i);
2777 CGM.getDiags().Report(OutExpr->getExprLoc(),
2778 diag::err_store_value_to_reg);
2779 return;
2780 }
2781 Dest = CGF.MakeAddrLValue(A, Ty);
2782 }
2783 CGF.EmitStoreThroughLValue(RValue::get(Tmp), Dest);
2784 }
2785 }
2786
EmitHipStdParUnsupportedAsm(CodeGenFunction * CGF,const AsmStmt & S)2787 static void EmitHipStdParUnsupportedAsm(CodeGenFunction *CGF,
2788 const AsmStmt &S) {
2789 constexpr auto Name = "__ASM__hipstdpar_unsupported";
2790
2791 std::string Asm;
2792 if (auto GCCAsm = dyn_cast<GCCAsmStmt>(&S))
2793 Asm = GCCAsm->getAsmString();
2794
2795 auto &Ctx = CGF->CGM.getLLVMContext();
2796
2797 auto StrTy = llvm::ConstantDataArray::getString(Ctx, Asm);
2798 auto FnTy = llvm::FunctionType::get(llvm::Type::getVoidTy(Ctx),
2799 {StrTy->getType()}, false);
2800 auto UBF = CGF->CGM.getModule().getOrInsertFunction(Name, FnTy);
2801
2802 CGF->Builder.CreateCall(UBF, {StrTy});
2803 }
2804
EmitAsmStmt(const AsmStmt & S)2805 void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
2806 // Pop all cleanup blocks at the end of the asm statement.
2807 CodeGenFunction::RunCleanupsScope Cleanups(*this);
2808
2809 // Assemble the final asm string.
2810 std::string AsmString = S.generateAsmString(getContext());
2811
2812 // Get all the output and input constraints together.
2813 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
2814 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
2815
2816 bool IsHipStdPar = getLangOpts().HIPStdPar && getLangOpts().CUDAIsDevice;
2817 bool IsValidTargetAsm = true;
2818 for (unsigned i = 0, e = S.getNumOutputs(); i != e && IsValidTargetAsm; i++) {
2819 StringRef Name;
2820 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S))
2821 Name = GAS->getOutputName(i);
2822 TargetInfo::ConstraintInfo Info(S.getOutputConstraint(i), Name);
2823 bool IsValid = getTarget().validateOutputConstraint(Info); (void)IsValid;
2824 if (IsHipStdPar && !IsValid)
2825 IsValidTargetAsm = false;
2826 else
2827 assert(IsValid && "Failed to parse output constraint");
2828 OutputConstraintInfos.push_back(Info);
2829 }
2830
2831 for (unsigned i = 0, e = S.getNumInputs(); i != e && IsValidTargetAsm; i++) {
2832 StringRef Name;
2833 if (const GCCAsmStmt *GAS = dyn_cast<GCCAsmStmt>(&S))
2834 Name = GAS->getInputName(i);
2835 TargetInfo::ConstraintInfo Info(S.getInputConstraint(i), Name);
2836 bool IsValid =
2837 getTarget().validateInputConstraint(OutputConstraintInfos, Info);
2838 if (IsHipStdPar && !IsValid)
2839 IsValidTargetAsm = false;
2840 else
2841 assert(IsValid && "Failed to parse input constraint");
2842 InputConstraintInfos.push_back(Info);
2843 }
2844
2845 if (!IsValidTargetAsm)
2846 return EmitHipStdParUnsupportedAsm(this, S);
2847
2848 std::string Constraints;
2849
2850 std::vector<LValue> ResultRegDests;
2851 std::vector<QualType> ResultRegQualTys;
2852 std::vector<llvm::Type *> ResultRegTypes;
2853 std::vector<llvm::Type *> ResultTruncRegTypes;
2854 std::vector<llvm::Type *> ArgTypes;
2855 std::vector<llvm::Type *> ArgElemTypes;
2856 std::vector<llvm::Value*> Args;
2857 llvm::BitVector ResultTypeRequiresCast;
2858 llvm::BitVector ResultRegIsFlagReg;
2859
2860 // Keep track of inout constraints.
2861 std::string InOutConstraints;
2862 std::vector<llvm::Value*> InOutArgs;
2863 std::vector<llvm::Type*> InOutArgTypes;
2864 std::vector<llvm::Type*> InOutArgElemTypes;
2865
2866 // Keep track of out constraints for tied input operand.
2867 std::vector<std::string> OutputConstraints;
2868
2869 // Keep track of defined physregs.
2870 llvm::SmallSet<std::string, 8> PhysRegOutputs;
2871
2872 // An inline asm can be marked readonly if it meets the following conditions:
2873 // - it doesn't have any sideeffects
2874 // - it doesn't clobber memory
2875 // - it doesn't return a value by-reference
2876 // It can be marked readnone if it doesn't have any input memory constraints
2877 // in addition to meeting the conditions listed above.
2878 bool ReadOnly = true, ReadNone = true;
2879
2880 for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) {
2881 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
2882
2883 // Simplify the output constraint.
2884 std::string OutputConstraint(S.getOutputConstraint(i));
2885 OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1,
2886 getTarget(), &OutputConstraintInfos);
2887
2888 const Expr *OutExpr = S.getOutputExpr(i);
2889 OutExpr = OutExpr->IgnoreParenNoopCasts(getContext());
2890
2891 std::string GCCReg;
2892 OutputConstraint = AddVariableConstraints(OutputConstraint, *OutExpr,
2893 getTarget(), CGM, S,
2894 Info.earlyClobber(),
2895 &GCCReg);
2896 // Give an error on multiple outputs to same physreg.
2897 if (!GCCReg.empty() && !PhysRegOutputs.insert(GCCReg).second)
2898 CGM.Error(S.getAsmLoc(), "multiple outputs to hard register: " + GCCReg);
2899
2900 OutputConstraints.push_back(OutputConstraint);
2901 LValue Dest = EmitLValue(OutExpr);
2902 if (!Constraints.empty())
2903 Constraints += ',';
2904
2905 // If this is a register output, then make the inline asm return it
2906 // by-value. If this is a memory result, return the value by-reference.
2907 QualType QTy = OutExpr->getType();
2908 const bool IsScalarOrAggregate = hasScalarEvaluationKind(QTy) ||
2909 hasAggregateEvaluationKind(QTy);
2910 if (!Info.allowsMemory() && IsScalarOrAggregate) {
2911
2912 Constraints += "=" + OutputConstraint;
2913 ResultRegQualTys.push_back(QTy);
2914 ResultRegDests.push_back(Dest);
2915
2916 bool IsFlagReg = llvm::StringRef(OutputConstraint).starts_with("{@cc");
2917 ResultRegIsFlagReg.push_back(IsFlagReg);
2918
2919 llvm::Type *Ty = ConvertTypeForMem(QTy);
2920 const bool RequiresCast = Info.allowsRegister() &&
2921 (getTargetHooks().isScalarizableAsmOperand(*this, Ty) ||
2922 Ty->isAggregateType());
2923
2924 ResultTruncRegTypes.push_back(Ty);
2925 ResultTypeRequiresCast.push_back(RequiresCast);
2926
2927 if (RequiresCast) {
2928 unsigned Size = getContext().getTypeSize(QTy);
2929 if (Size)
2930 Ty = llvm::IntegerType::get(getLLVMContext(), Size);
2931 else
2932 CGM.Error(OutExpr->getExprLoc(), "output size should not be zero");
2933 }
2934 ResultRegTypes.push_back(Ty);
2935 // If this output is tied to an input, and if the input is larger, then
2936 // we need to set the actual result type of the inline asm node to be the
2937 // same as the input type.
2938 if (Info.hasMatchingInput()) {
2939 unsigned InputNo;
2940 for (InputNo = 0; InputNo != S.getNumInputs(); ++InputNo) {
2941 TargetInfo::ConstraintInfo &Input = InputConstraintInfos[InputNo];
2942 if (Input.hasTiedOperand() && Input.getTiedOperand() == i)
2943 break;
2944 }
2945 assert(InputNo != S.getNumInputs() && "Didn't find matching input!");
2946
2947 QualType InputTy = S.getInputExpr(InputNo)->getType();
2948 QualType OutputType = OutExpr->getType();
2949
2950 uint64_t InputSize = getContext().getTypeSize(InputTy);
2951 if (getContext().getTypeSize(OutputType) < InputSize) {
2952 // Form the asm to return the value as a larger integer or fp type.
2953 ResultRegTypes.back() = ConvertType(InputTy);
2954 }
2955 }
2956 if (llvm::Type* AdjTy =
2957 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint,
2958 ResultRegTypes.back()))
2959 ResultRegTypes.back() = AdjTy;
2960 else {
2961 CGM.getDiags().Report(S.getAsmLoc(),
2962 diag::err_asm_invalid_type_in_input)
2963 << OutExpr->getType() << OutputConstraint;
2964 }
2965
2966 // Update largest vector width for any vector types.
2967 if (auto *VT = dyn_cast<llvm::VectorType>(ResultRegTypes.back()))
2968 LargestVectorWidth =
2969 std::max((uint64_t)LargestVectorWidth,
2970 VT->getPrimitiveSizeInBits().getKnownMinValue());
2971 } else {
2972 Address DestAddr = Dest.getAddress();
2973 // Matrix types in memory are represented by arrays, but accessed through
2974 // vector pointers, with the alignment specified on the access operation.
2975 // For inline assembly, update pointer arguments to use vector pointers.
2976 // Otherwise there will be a mis-match if the matrix is also an
2977 // input-argument which is represented as vector.
2978 if (isa<MatrixType>(OutExpr->getType().getCanonicalType()))
2979 DestAddr = DestAddr.withElementType(ConvertType(OutExpr->getType()));
2980
2981 ArgTypes.push_back(DestAddr.getType());
2982 ArgElemTypes.push_back(DestAddr.getElementType());
2983 Args.push_back(DestAddr.emitRawPointer(*this));
2984 Constraints += "=*";
2985 Constraints += OutputConstraint;
2986 ReadOnly = ReadNone = false;
2987 }
2988
2989 if (Info.isReadWrite()) {
2990 InOutConstraints += ',';
2991
2992 const Expr *InputExpr = S.getOutputExpr(i);
2993 llvm::Value *Arg;
2994 llvm::Type *ArgElemType;
2995 std::tie(Arg, ArgElemType) = EmitAsmInputLValue(
2996 Info, Dest, InputExpr->getType(), InOutConstraints,
2997 InputExpr->getExprLoc());
2998
2999 if (llvm::Type* AdjTy =
3000 getTargetHooks().adjustInlineAsmType(*this, OutputConstraint,
3001 Arg->getType()))
3002 Arg = Builder.CreateBitCast(Arg, AdjTy);
3003
3004 // Update largest vector width for any vector types.
3005 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType()))
3006 LargestVectorWidth =
3007 std::max((uint64_t)LargestVectorWidth,
3008 VT->getPrimitiveSizeInBits().getKnownMinValue());
3009 // Only tie earlyclobber physregs.
3010 if (Info.allowsRegister() && (GCCReg.empty() || Info.earlyClobber()))
3011 InOutConstraints += llvm::utostr(i);
3012 else
3013 InOutConstraints += OutputConstraint;
3014
3015 InOutArgTypes.push_back(Arg->getType());
3016 InOutArgElemTypes.push_back(ArgElemType);
3017 InOutArgs.push_back(Arg);
3018 }
3019 }
3020
3021 // If this is a Microsoft-style asm blob, store the return registers (EAX:EDX)
3022 // to the return value slot. Only do this when returning in registers.
3023 if (isa<MSAsmStmt>(&S)) {
3024 const ABIArgInfo &RetAI = CurFnInfo->getReturnInfo();
3025 if (RetAI.isDirect() || RetAI.isExtend()) {
3026 // Make a fake lvalue for the return value slot.
3027 LValue ReturnSlot = MakeAddrLValueWithoutTBAA(ReturnValue, FnRetTy);
3028 CGM.getTargetCodeGenInfo().addReturnRegisterOutputs(
3029 *this, ReturnSlot, Constraints, ResultRegTypes, ResultTruncRegTypes,
3030 ResultRegDests, AsmString, S.getNumOutputs());
3031 SawAsmBlock = true;
3032 }
3033 }
3034
3035 for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) {
3036 const Expr *InputExpr = S.getInputExpr(i);
3037
3038 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
3039
3040 if (Info.allowsMemory())
3041 ReadNone = false;
3042
3043 if (!Constraints.empty())
3044 Constraints += ',';
3045
3046 // Simplify the input constraint.
3047 std::string InputConstraint(S.getInputConstraint(i));
3048 InputConstraint = SimplifyConstraint(InputConstraint.c_str(), getTarget(),
3049 &OutputConstraintInfos);
3050
3051 InputConstraint = AddVariableConstraints(
3052 InputConstraint, *InputExpr->IgnoreParenNoopCasts(getContext()),
3053 getTarget(), CGM, S, false /* No EarlyClobber */);
3054
3055 std::string ReplaceConstraint (InputConstraint);
3056 llvm::Value *Arg;
3057 llvm::Type *ArgElemType;
3058 std::tie(Arg, ArgElemType) = EmitAsmInput(Info, InputExpr, Constraints);
3059
3060 // If this input argument is tied to a larger output result, extend the
3061 // input to be the same size as the output. The LLVM backend wants to see
3062 // the input and output of a matching constraint be the same size. Note
3063 // that GCC does not define what the top bits are here. We use zext because
3064 // that is usually cheaper, but LLVM IR should really get an anyext someday.
3065 if (Info.hasTiedOperand()) {
3066 unsigned Output = Info.getTiedOperand();
3067 QualType OutputType = S.getOutputExpr(Output)->getType();
3068 QualType InputTy = InputExpr->getType();
3069
3070 if (getContext().getTypeSize(OutputType) >
3071 getContext().getTypeSize(InputTy)) {
3072 // Use ptrtoint as appropriate so that we can do our extension.
3073 if (isa<llvm::PointerType>(Arg->getType()))
3074 Arg = Builder.CreatePtrToInt(Arg, IntPtrTy);
3075 llvm::Type *OutputTy = ConvertType(OutputType);
3076 if (isa<llvm::IntegerType>(OutputTy))
3077 Arg = Builder.CreateZExt(Arg, OutputTy);
3078 else if (isa<llvm::PointerType>(OutputTy))
3079 Arg = Builder.CreateZExt(Arg, IntPtrTy);
3080 else if (OutputTy->isFloatingPointTy())
3081 Arg = Builder.CreateFPExt(Arg, OutputTy);
3082 }
3083 // Deal with the tied operands' constraint code in adjustInlineAsmType.
3084 ReplaceConstraint = OutputConstraints[Output];
3085 }
3086 if (llvm::Type* AdjTy =
3087 getTargetHooks().adjustInlineAsmType(*this, ReplaceConstraint,
3088 Arg->getType()))
3089 Arg = Builder.CreateBitCast(Arg, AdjTy);
3090 else
3091 CGM.getDiags().Report(S.getAsmLoc(), diag::err_asm_invalid_type_in_input)
3092 << InputExpr->getType() << InputConstraint;
3093
3094 // Update largest vector width for any vector types.
3095 if (auto *VT = dyn_cast<llvm::VectorType>(Arg->getType()))
3096 LargestVectorWidth =
3097 std::max((uint64_t)LargestVectorWidth,
3098 VT->getPrimitiveSizeInBits().getKnownMinValue());
3099
3100 ArgTypes.push_back(Arg->getType());
3101 ArgElemTypes.push_back(ArgElemType);
3102 Args.push_back(Arg);
3103 Constraints += InputConstraint;
3104 }
3105
3106 // Append the "input" part of inout constraints.
3107 for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) {
3108 ArgTypes.push_back(InOutArgTypes[i]);
3109 ArgElemTypes.push_back(InOutArgElemTypes[i]);
3110 Args.push_back(InOutArgs[i]);
3111 }
3112 Constraints += InOutConstraints;
3113
3114 // Labels
3115 SmallVector<llvm::BasicBlock *, 16> Transfer;
3116 llvm::BasicBlock *Fallthrough = nullptr;
3117 bool IsGCCAsmGoto = false;
3118 if (const auto *GS = dyn_cast<GCCAsmStmt>(&S)) {
3119 IsGCCAsmGoto = GS->isAsmGoto();
3120 if (IsGCCAsmGoto) {
3121 for (const auto *E : GS->labels()) {
3122 JumpDest Dest = getJumpDestForLabel(E->getLabel());
3123 Transfer.push_back(Dest.getBlock());
3124 if (!Constraints.empty())
3125 Constraints += ',';
3126 Constraints += "!i";
3127 }
3128 Fallthrough = createBasicBlock("asm.fallthrough");
3129 }
3130 }
3131
3132 bool HasUnwindClobber = false;
3133
3134 // Clobbers
3135 for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) {
3136 std::string Clobber = S.getClobber(i);
3137
3138 if (Clobber == "memory")
3139 ReadOnly = ReadNone = false;
3140 else if (Clobber == "unwind") {
3141 HasUnwindClobber = true;
3142 continue;
3143 } else if (Clobber != "cc") {
3144 Clobber = getTarget().getNormalizedGCCRegisterName(Clobber);
3145 if (CGM.getCodeGenOpts().StackClashProtector &&
3146 getTarget().isSPRegName(Clobber)) {
3147 CGM.getDiags().Report(S.getAsmLoc(),
3148 diag::warn_stack_clash_protection_inline_asm);
3149 }
3150 }
3151
3152 if (isa<MSAsmStmt>(&S)) {
3153 if (Clobber == "eax" || Clobber == "edx") {
3154 if (Constraints.find("=&A") != std::string::npos)
3155 continue;
3156 std::string::size_type position1 =
3157 Constraints.find("={" + Clobber + "}");
3158 if (position1 != std::string::npos) {
3159 Constraints.insert(position1 + 1, "&");
3160 continue;
3161 }
3162 std::string::size_type position2 = Constraints.find("=A");
3163 if (position2 != std::string::npos) {
3164 Constraints.insert(position2 + 1, "&");
3165 continue;
3166 }
3167 }
3168 }
3169 if (!Constraints.empty())
3170 Constraints += ',';
3171
3172 Constraints += "~{";
3173 Constraints += Clobber;
3174 Constraints += '}';
3175 }
3176
3177 assert(!(HasUnwindClobber && IsGCCAsmGoto) &&
3178 "unwind clobber can't be used with asm goto");
3179
3180 // Add machine specific clobbers
3181 std::string_view MachineClobbers = getTarget().getClobbers();
3182 if (!MachineClobbers.empty()) {
3183 if (!Constraints.empty())
3184 Constraints += ',';
3185 Constraints += MachineClobbers;
3186 }
3187
3188 llvm::Type *ResultType;
3189 if (ResultRegTypes.empty())
3190 ResultType = VoidTy;
3191 else if (ResultRegTypes.size() == 1)
3192 ResultType = ResultRegTypes[0];
3193 else
3194 ResultType = llvm::StructType::get(getLLVMContext(), ResultRegTypes);
3195
3196 llvm::FunctionType *FTy =
3197 llvm::FunctionType::get(ResultType, ArgTypes, false);
3198
3199 bool HasSideEffect = S.isVolatile() || S.getNumOutputs() == 0;
3200
3201 llvm::InlineAsm::AsmDialect GnuAsmDialect =
3202 CGM.getCodeGenOpts().getInlineAsmDialect() == CodeGenOptions::IAD_ATT
3203 ? llvm::InlineAsm::AD_ATT
3204 : llvm::InlineAsm::AD_Intel;
3205 llvm::InlineAsm::AsmDialect AsmDialect = isa<MSAsmStmt>(&S) ?
3206 llvm::InlineAsm::AD_Intel : GnuAsmDialect;
3207
3208 llvm::InlineAsm *IA = llvm::InlineAsm::get(
3209 FTy, AsmString, Constraints, HasSideEffect,
3210 /* IsAlignStack */ false, AsmDialect, HasUnwindClobber);
3211 std::vector<llvm::Value*> RegResults;
3212 llvm::CallBrInst *CBR;
3213 llvm::DenseMap<llvm::BasicBlock *, SmallVector<llvm::Value *, 4>>
3214 CBRRegResults;
3215 if (IsGCCAsmGoto) {
3216 CBR = Builder.CreateCallBr(IA, Fallthrough, Transfer, Args);
3217 EmitBlock(Fallthrough);
3218 UpdateAsmCallInst(*CBR, HasSideEffect, /*HasUnwindClobber=*/false, ReadOnly,
3219 ReadNone, InNoMergeAttributedStmt,
3220 InNoConvergentAttributedStmt, S, ResultRegTypes,
3221 ArgElemTypes, *this, RegResults);
3222 // Because we are emitting code top to bottom, we don't have enough
3223 // information at this point to know precisely whether we have a critical
3224 // edge. If we have outputs, split all indirect destinations.
3225 if (!RegResults.empty()) {
3226 unsigned i = 0;
3227 for (llvm::BasicBlock *Dest : CBR->getIndirectDests()) {
3228 llvm::Twine SynthName = Dest->getName() + ".split";
3229 llvm::BasicBlock *SynthBB = createBasicBlock(SynthName);
3230 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
3231 Builder.SetInsertPoint(SynthBB);
3232
3233 if (ResultRegTypes.size() == 1) {
3234 CBRRegResults[SynthBB].push_back(CBR);
3235 } else {
3236 for (unsigned j = 0, e = ResultRegTypes.size(); j != e; ++j) {
3237 llvm::Value *Tmp = Builder.CreateExtractValue(CBR, j, "asmresult");
3238 CBRRegResults[SynthBB].push_back(Tmp);
3239 }
3240 }
3241
3242 EmitBranch(Dest);
3243 EmitBlock(SynthBB);
3244 CBR->setIndirectDest(i++, SynthBB);
3245 }
3246 }
3247 } else if (HasUnwindClobber) {
3248 llvm::CallBase *Result = EmitCallOrInvoke(IA, Args, "");
3249 UpdateAsmCallInst(*Result, HasSideEffect, /*HasUnwindClobber=*/true,
3250 ReadOnly, ReadNone, InNoMergeAttributedStmt,
3251 InNoConvergentAttributedStmt, S, ResultRegTypes,
3252 ArgElemTypes, *this, RegResults);
3253 } else {
3254 llvm::CallInst *Result =
3255 Builder.CreateCall(IA, Args, getBundlesForFunclet(IA));
3256 UpdateAsmCallInst(*Result, HasSideEffect, /*HasUnwindClobber=*/false,
3257 ReadOnly, ReadNone, InNoMergeAttributedStmt,
3258 InNoConvergentAttributedStmt, S, ResultRegTypes,
3259 ArgElemTypes, *this, RegResults);
3260 }
3261
3262 EmitAsmStores(*this, S, RegResults, ResultRegTypes, ResultTruncRegTypes,
3263 ResultRegDests, ResultRegQualTys, ResultTypeRequiresCast,
3264 ResultRegIsFlagReg);
3265
3266 // If this is an asm goto with outputs, repeat EmitAsmStores, but with a
3267 // different insertion point; one for each indirect destination and with
3268 // CBRRegResults rather than RegResults.
3269 if (IsGCCAsmGoto && !CBRRegResults.empty()) {
3270 for (llvm::BasicBlock *Succ : CBR->getIndirectDests()) {
3271 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
3272 Builder.SetInsertPoint(Succ, --(Succ->end()));
3273 EmitAsmStores(*this, S, CBRRegResults[Succ], ResultRegTypes,
3274 ResultTruncRegTypes, ResultRegDests, ResultRegQualTys,
3275 ResultTypeRequiresCast, ResultRegIsFlagReg);
3276 }
3277 }
3278 }
3279
InitCapturedStruct(const CapturedStmt & S)3280 LValue CodeGenFunction::InitCapturedStruct(const CapturedStmt &S) {
3281 const RecordDecl *RD = S.getCapturedRecordDecl();
3282 QualType RecordTy = getContext().getRecordType(RD);
3283
3284 // Initialize the captured struct.
3285 LValue SlotLV =
3286 MakeAddrLValue(CreateMemTemp(RecordTy, "agg.captured"), RecordTy);
3287
3288 RecordDecl::field_iterator CurField = RD->field_begin();
3289 for (CapturedStmt::const_capture_init_iterator I = S.capture_init_begin(),
3290 E = S.capture_init_end();
3291 I != E; ++I, ++CurField) {
3292 LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField);
3293 if (CurField->hasCapturedVLAType()) {
3294 EmitLambdaVLACapture(CurField->getCapturedVLAType(), LV);
3295 } else {
3296 EmitInitializerForField(*CurField, LV, *I);
3297 }
3298 }
3299
3300 return SlotLV;
3301 }
3302
3303 /// Generate an outlined function for the body of a CapturedStmt, store any
3304 /// captured variables into the captured struct, and call the outlined function.
3305 llvm::Function *
EmitCapturedStmt(const CapturedStmt & S,CapturedRegionKind K)3306 CodeGenFunction::EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K) {
3307 LValue CapStruct = InitCapturedStruct(S);
3308
3309 // Emit the CapturedDecl
3310 CodeGenFunction CGF(CGM, true);
3311 CGCapturedStmtRAII CapInfoRAII(CGF, new CGCapturedStmtInfo(S, K));
3312 llvm::Function *F = CGF.GenerateCapturedStmtFunction(S);
3313 delete CGF.CapturedStmtInfo;
3314
3315 // Emit call to the helper function.
3316 EmitCallOrInvoke(F, CapStruct.getPointer(*this));
3317
3318 return F;
3319 }
3320
GenerateCapturedStmtArgument(const CapturedStmt & S)3321 Address CodeGenFunction::GenerateCapturedStmtArgument(const CapturedStmt &S) {
3322 LValue CapStruct = InitCapturedStruct(S);
3323 return CapStruct.getAddress();
3324 }
3325
3326 /// Creates the outlined function for a CapturedStmt.
3327 llvm::Function *
GenerateCapturedStmtFunction(const CapturedStmt & S)3328 CodeGenFunction::GenerateCapturedStmtFunction(const CapturedStmt &S) {
3329 assert(CapturedStmtInfo &&
3330 "CapturedStmtInfo should be set when generating the captured function");
3331 const CapturedDecl *CD = S.getCapturedDecl();
3332 const RecordDecl *RD = S.getCapturedRecordDecl();
3333 SourceLocation Loc = S.getBeginLoc();
3334 assert(CD->hasBody() && "missing CapturedDecl body");
3335
3336 // Build the argument list.
3337 ASTContext &Ctx = CGM.getContext();
3338 FunctionArgList Args;
3339 Args.append(CD->param_begin(), CD->param_end());
3340
3341 // Create the function declaration.
3342 const CGFunctionInfo &FuncInfo =
3343 CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, Args);
3344 llvm::FunctionType *FuncLLVMTy = CGM.getTypes().GetFunctionType(FuncInfo);
3345
3346 llvm::Function *F =
3347 llvm::Function::Create(FuncLLVMTy, llvm::GlobalValue::InternalLinkage,
3348 CapturedStmtInfo->getHelperName(), &CGM.getModule());
3349 CGM.SetInternalFunctionAttributes(CD, F, FuncInfo);
3350 if (CD->isNothrow())
3351 F->addFnAttr(llvm::Attribute::NoUnwind);
3352
3353 // Generate the function.
3354 StartFunction(CD, Ctx.VoidTy, F, FuncInfo, Args, CD->getLocation(),
3355 CD->getBody()->getBeginLoc());
3356 // Set the context parameter in CapturedStmtInfo.
3357 Address DeclPtr = GetAddrOfLocalVar(CD->getContextParam());
3358 CapturedStmtInfo->setContextValue(Builder.CreateLoad(DeclPtr));
3359
3360 // Initialize variable-length arrays.
3361 LValue Base = MakeNaturalAlignRawAddrLValue(
3362 CapturedStmtInfo->getContextValue(), Ctx.getTagDeclType(RD));
3363 for (auto *FD : RD->fields()) {
3364 if (FD->hasCapturedVLAType()) {
3365 auto *ExprArg =
3366 EmitLoadOfLValue(EmitLValueForField(Base, FD), S.getBeginLoc())
3367 .getScalarVal();
3368 auto VAT = FD->getCapturedVLAType();
3369 VLASizeMap[VAT->getSizeExpr()] = ExprArg;
3370 }
3371 }
3372
3373 // If 'this' is captured, load it into CXXThisValue.
3374 if (CapturedStmtInfo->isCXXThisExprCaptured()) {
3375 FieldDecl *FD = CapturedStmtInfo->getThisFieldDecl();
3376 LValue ThisLValue = EmitLValueForField(Base, FD);
3377 CXXThisValue = EmitLoadOfLValue(ThisLValue, Loc).getScalarVal();
3378 }
3379
3380 PGO->assignRegionCounters(GlobalDecl(CD), F);
3381 CapturedStmtInfo->EmitBody(*this, CD->getBody());
3382 FinishFunction(CD->getBodyRBrace());
3383
3384 return F;
3385 }
3386
3387 // Returns the first convergence entry/loop/anchor instruction found in |BB|.
3388 // std::nullptr otherwise.
getConvergenceToken(llvm::BasicBlock * BB)3389 static llvm::ConvergenceControlInst *getConvergenceToken(llvm::BasicBlock *BB) {
3390 for (auto &I : *BB) {
3391 if (auto *CI = dyn_cast<llvm::ConvergenceControlInst>(&I))
3392 return CI;
3393 }
3394 return nullptr;
3395 }
3396
3397 llvm::CallBase *
addConvergenceControlToken(llvm::CallBase * Input)3398 CodeGenFunction::addConvergenceControlToken(llvm::CallBase *Input) {
3399 llvm::ConvergenceControlInst *ParentToken = ConvergenceTokenStack.back();
3400 assert(ParentToken);
3401
3402 llvm::Value *bundleArgs[] = {ParentToken};
3403 llvm::OperandBundleDef OB("convergencectrl", bundleArgs);
3404 auto *Output = llvm::CallBase::addOperandBundle(
3405 Input, llvm::LLVMContext::OB_convergencectrl, OB, Input->getIterator());
3406 Input->replaceAllUsesWith(Output);
3407 Input->eraseFromParent();
3408 return Output;
3409 }
3410
3411 llvm::ConvergenceControlInst *
emitConvergenceLoopToken(llvm::BasicBlock * BB)3412 CodeGenFunction::emitConvergenceLoopToken(llvm::BasicBlock *BB) {
3413 llvm::ConvergenceControlInst *ParentToken = ConvergenceTokenStack.back();
3414 assert(ParentToken);
3415 return llvm::ConvergenceControlInst::CreateLoop(*BB, ParentToken);
3416 }
3417
3418 llvm::ConvergenceControlInst *
getOrEmitConvergenceEntryToken(llvm::Function * F)3419 CodeGenFunction::getOrEmitConvergenceEntryToken(llvm::Function *F) {
3420 llvm::BasicBlock *BB = &F->getEntryBlock();
3421 llvm::ConvergenceControlInst *Token = getConvergenceToken(BB);
3422 if (Token)
3423 return Token;
3424
3425 // Adding a convergence token requires the function to be marked as
3426 // convergent.
3427 F->setConvergent();
3428 return llvm::ConvergenceControlInst::CreateEntry(*BB);
3429 }
3430